--- _id: '64551' abstract: - lang: eng text: Laterally coupled vertical-cavity surface-emitting lasers (VCSELs) can exhibit additional resonances at high modulation frequencies that can substantially increase the laser’s modulation bandwidth. State-of-the-art laterally coupled devices require non-standard manufacturing technology and precise tuning of the currents supplied to each cavity separately to form optical supermodes suitable for such resonances. Here, we report on a novel switching phenomenon in laterally coupled VCSEL structures having only a single common electric contact and manufactured in a standard oxide-confined VCSEL geometry. At lower currents, they can be operated in a weakly coupled (WCR) regime and, at higher currents, in an injection-locked (IL) regime, enabling fundamentally different spectral and dynamic features. In the WCR, both optical supermodes lase and a narrow tunable plasma-assisted peak at their beating frequency is observed for each of the apertures, with a current-dependent frequency tuning and anti-phase intensity oscillations in each of the cavities. In contrast, in the IL regimes, only one (anti-symmetric) supermode lases. This adds a broader resonance to the modulation response while the intensity oscillations in both cavities are in-phase. Only the IL regime can result in increased modulation bandwidth of the system. Measurements of the pulse responses and continuous modulation up to 70 GHz for both operational regimes are presented and compared with simulations of our distributed rate equation model whose parameters are extracted from full-wave electromagnetic simulations of the device, including the temperature distribution in the device. Excellent agreement is found and enables comprehensive understanding of the dynamics of supermodes in oxide-confined coupled cavity VCSELs. article_number: '053102' author: - first_name: M. full_name: Lindemann, M. last_name: Lindemann - first_name: M. full_name: D’Alessandro, M. last_name: D’Alessandro - first_name: N. full_name: Ledentsov, N. last_name: Ledentsov - first_name: O. Y. full_name: Makarov, O. Y. last_name: Makarov - first_name: N. N. full_name: Ledentsov, N. N. last_name: Ledentsov - first_name: A. full_name: Tibaldi, A. last_name: Tibaldi - first_name: Nils Christopher full_name: Gerhardt, Nils Christopher id: '115298' last_name: Gerhardt orcid: 0009-0002-5538-231X - first_name: M. R. full_name: Hofmann, M. R. last_name: Hofmann citation: ama: Lindemann M, D’Alessandro M, Ledentsov N, et al. Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics. 2025;138(5). doi:10.1063/5.0275622 apa: Lindemann, M., D’Alessandro, M., Ledentsov, N., Makarov, O. Y., Ledentsov, N. N., Tibaldi, A., Gerhardt, N. C., & Hofmann, M. R. (2025). Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics, 138(5), Article 053102. https://doi.org/10.1063/5.0275622 bibtex: '@article{Lindemann_D’Alessandro_Ledentsov_Makarov_Ledentsov_Tibaldi_Gerhardt_Hofmann_2025, title={Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency}, volume={138}, DOI={10.1063/5.0275622}, number={5053102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Lindemann, M. and D’Alessandro, M. and Ledentsov, N. and Makarov, O. Y. and Ledentsov, N. N. and Tibaldi, A. and Gerhardt, Nils Christopher and Hofmann, M. R.}, year={2025} }' chicago: Lindemann, M., M. D’Alessandro, N. Ledentsov, O. Y. Makarov, N. N. Ledentsov, A. Tibaldi, Nils Christopher Gerhardt, and M. R. Hofmann. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics 138, no. 5 (2025). https://doi.org/10.1063/5.0275622. ieee: 'M. Lindemann et al., “Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency,” Journal of Applied Physics, vol. 138, no. 5, Art. no. 053102, 2025, doi: 10.1063/5.0275622.' mla: Lindemann, M., et al. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics, vol. 138, no. 5, 053102, AIP Publishing, 2025, doi:10.1063/5.0275622. short: M. Lindemann, M. D’Alessandro, N. Ledentsov, O.Y. Makarov, N.N. Ledentsov, A. Tibaldi, N.C. Gerhardt, M.R. Hofmann, Journal of Applied Physics 138 (2025). date_created: 2026-02-20T11:11:12Z date_updated: 2026-02-20T11:15:05Z department: - _id: '977' doi: 10.1063/5.0275622 intvolume: ' 138' issue: '5' language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Laterally coupled vertical-cavity surface-emitting lasers with tunable resonance width and frequency type: journal_article user_id: '15911' volume: 138 year: '2025' ... --- _id: '61337' abstract: - lang: eng text: Lithium niobate–tantalate mixed (LNT) crystals promise improved performance and new applications for optical, piezomechanical, or electrical devices when compared to the end composition compounds lithium niobate and lithium tantalate. The macroscopic properties of ferroelectrics highly depend on the structure of the underlying ferroelectric domains, which within mixed crystals can interact with the local changes in chemical compositions. In this work, we demonstrate how ferroelectric domain walls can unambiguously be identified and distinguished from local changes in composition by correlating piezoresponse force microscopy with second harmonic generation microscopy, using the Cherenkov contrast, reference crystal contrast, and negative phase mismatching contrast. We demonstrate how measuring the associated intensity change when approaching negative phase mismatching can be used to deduce the local tantalum concentration fast and over a large sample area. Based on these results, we study the natural domain structures that appear from Czochralski-grown, multi-domain LNT solid solution crystals. The developed results and methods serve as the central foundation to poling these mixed crystal systems and are key for their integration and applications. article_number: '034101' author: - first_name: Boris full_name: Koppitz, Boris last_name: Koppitz - first_name: Tanya full_name: Saxena, Tanya last_name: Saxena - first_name: Felix full_name: Bernhardt, Felix last_name: Bernhardt - first_name: Steffen full_name: Ganschow, Steffen last_name: Ganschow - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng citation: ama: Koppitz B, Saxena T, Bernhardt F, et al. Second harmonic generation contrasts of ferroelectric domain structures and composition in lithium niobate–tantalate mixed crystals. Journal of Applied Physics. 2025;138(3). doi:10.1063/5.0276183 apa: Koppitz, B., Saxena, T., Bernhardt, F., Ganschow, S., Sanna, S., Rüsing, M., & Eng, L. M. (2025). Second harmonic generation contrasts of ferroelectric domain structures and composition in lithium niobate–tantalate mixed crystals. Journal of Applied Physics, 138(3), Article 034101. https://doi.org/10.1063/5.0276183 bibtex: '@article{Koppitz_Saxena_Bernhardt_Ganschow_Sanna_Rüsing_Eng_2025, title={Second harmonic generation contrasts of ferroelectric domain structures and composition in lithium niobate–tantalate mixed crystals}, volume={138}, DOI={10.1063/5.0276183}, number={3034101}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Koppitz, Boris and Saxena, Tanya and Bernhardt, Felix and Ganschow, Steffen and Sanna, Simone and Rüsing, Michael and Eng, Lukas M.}, year={2025} }' chicago: Koppitz, Boris, Tanya Saxena, Felix Bernhardt, Steffen Ganschow, Simone Sanna, Michael Rüsing, and Lukas M. Eng. “Second Harmonic Generation Contrasts of Ferroelectric Domain Structures and Composition in Lithium Niobate–Tantalate Mixed Crystals.” Journal of Applied Physics 138, no. 3 (2025). https://doi.org/10.1063/5.0276183. ieee: 'B. Koppitz et al., “Second harmonic generation contrasts of ferroelectric domain structures and composition in lithium niobate–tantalate mixed crystals,” Journal of Applied Physics, vol. 138, no. 3, Art. no. 034101, 2025, doi: 10.1063/5.0276183.' mla: Koppitz, Boris, et al. “Second Harmonic Generation Contrasts of Ferroelectric Domain Structures and Composition in Lithium Niobate–Tantalate Mixed Crystals.” Journal of Applied Physics, vol. 138, no. 3, 034101, AIP Publishing, 2025, doi:10.1063/5.0276183. short: B. Koppitz, T. Saxena, F. Bernhardt, S. Ganschow, S. Sanna, M. Rüsing, L.M. Eng, Journal of Applied Physics 138 (2025). date_created: 2025-09-17T16:16:04Z date_updated: 2025-09-17T16:18:02Z department: - _id: '15' - _id: '623' doi: 10.1063/5.0276183 funded_apc: '1' intvolume: ' 138' issue: '3' language: - iso: eng main_file_link: - open_access: '1' url: https://pubs.aip.org/aip/jap/article/138/3/034101/3352909 oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Second harmonic generation contrasts of ferroelectric domain structures and composition in lithium niobate–tantalate mixed crystals type: journal_article user_id: '22501' volume: 138 year: '2025' ... --- _id: '61933' abstract: - lang: eng text: Laterally coupled vertical-cavity surface-emitting lasers (VCSELs) can exhibit additional resonances at high modulation frequencies that can substantially increase the laser’s modulation bandwidth. State-of-the-art laterally coupled devices require non-standard manufacturing technology and precise tuning of the currents supplied to each cavity separately to form optical supermodes suitable for such resonances. Here, we report on a novel switching phenomenon in laterally coupled VCSEL structures having only a single common electric contact and manufactured in a standard oxide-confined VCSEL geometry. At lower currents, they can be operated in a weakly coupled (WCR) regime and, at higher currents, in an injection-locked (IL) regime, enabling fundamentally different spectral and dynamic features. In the WCR, both optical supermodes lase and a narrow tunable plasma-assisted peak at their beating frequency is observed for each of the apertures, with a current-dependent frequency tuning and anti-phase intensity oscillations in each of the cavities. In contrast, in the IL regimes, only one (anti-symmetric) supermode lases. This adds a broader resonance to the modulation response while the intensity oscillations in both cavities are in-phase. Only the IL regime can result in increased modulation bandwidth of the system. Measurements of the pulse responses and continuous modulation up to 70 GHz for both operational regimes are presented and compared with simulations of our distributed rate equation model whose parameters are extracted from full-wave electromagnetic simulations of the device, including the temperature distribution in the device. Excellent agreement is found and enables comprehensive understanding of the dynamics of supermodes in oxide-confined coupled cavity VCSELs. article_number: '053102' author: - first_name: M. full_name: Lindemann, M. last_name: Lindemann - first_name: M. full_name: D’Alessandro, M. last_name: D’Alessandro - first_name: N. full_name: Ledentsov, N. last_name: Ledentsov - first_name: O. Y. full_name: Makarov, O. Y. last_name: Makarov - first_name: N. N. full_name: Ledentsov, N. N. last_name: Ledentsov - first_name: A. full_name: Tibaldi, A. last_name: Tibaldi - first_name: N. C. full_name: Gerhardt, N. C. last_name: Gerhardt - first_name: M. R. full_name: Hofmann, M. R. last_name: Hofmann citation: ama: Lindemann M, D’Alessandro M, Ledentsov N, et al. Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics. 2025;138(5). doi:10.1063/5.0275622 apa: Lindemann, M., D’Alessandro, M., Ledentsov, N., Makarov, O. Y., Ledentsov, N. N., Tibaldi, A., Gerhardt, N. C., & Hofmann, M. R. (2025). Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics, 138(5), Article 053102. https://doi.org/10.1063/5.0275622 bibtex: '@article{Lindemann_D’Alessandro_Ledentsov_Makarov_Ledentsov_Tibaldi_Gerhardt_Hofmann_2025, title={Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency}, volume={138}, DOI={10.1063/5.0275622}, number={5053102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Lindemann, M. and D’Alessandro, M. and Ledentsov, N. and Makarov, O. Y. and Ledentsov, N. N. and Tibaldi, A. and Gerhardt, N. C. and Hofmann, M. R.}, year={2025} }' chicago: Lindemann, M., M. D’Alessandro, N. Ledentsov, O. Y. Makarov, N. N. Ledentsov, A. Tibaldi, N. C. Gerhardt, and M. R. Hofmann. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics 138, no. 5 (2025). https://doi.org/10.1063/5.0275622. ieee: 'M. Lindemann et al., “Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency,” Journal of Applied Physics, vol. 138, no. 5, Art. no. 053102, 2025, doi: 10.1063/5.0275622.' mla: Lindemann, M., et al. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics, vol. 138, no. 5, 053102, AIP Publishing, 2025, doi:10.1063/5.0275622. short: M. Lindemann, M. D’Alessandro, N. Ledentsov, O.Y. Makarov, N.N. Ledentsov, A. Tibaldi, N.C. Gerhardt, M.R. Hofmann, Journal of Applied Physics 138 (2025). date_created: 2025-10-23T11:13:54Z date_updated: 2025-10-23T11:15:53Z doi: 10.1063/5.0275622 intvolume: ' 138' issue: '5' language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Laterally coupled vertical-cavity surface-emitting lasers with tunable resonance width and frequency type: journal_article user_id: '15911' volume: 138 year: '2025' ... --- _id: '61934' abstract: - lang: eng text: Laterally coupled vertical-cavity surface-emitting lasers (VCSELs) can exhibit additional resonances at high modulation frequencies that can substantially increase the laser’s modulation bandwidth. State-of-the-art laterally coupled devices require non-standard manufacturing technology and precise tuning of the currents supplied to each cavity separately to form optical supermodes suitable for such resonances. Here, we report on a novel switching phenomenon in laterally coupled VCSEL structures having only a single common electric contact and manufactured in a standard oxide-confined VCSEL geometry. At lower currents, they can be operated in a weakly coupled (WCR) regime and, at higher currents, in an injection-locked (IL) regime, enabling fundamentally different spectral and dynamic features. In the WCR, both optical supermodes lase and a narrow tunable plasma-assisted peak at their beating frequency is observed for each of the apertures, with a current-dependent frequency tuning and anti-phase intensity oscillations in each of the cavities. In contrast, in the IL regimes, only one (anti-symmetric) supermode lases. This adds a broader resonance to the modulation response while the intensity oscillations in both cavities are in-phase. Only the IL regime can result in increased modulation bandwidth of the system. Measurements of the pulse responses and continuous modulation up to 70 GHz for both operational regimes are presented and compared with simulations of our distributed rate equation model whose parameters are extracted from full-wave electromagnetic simulations of the device, including the temperature distribution in the device. Excellent agreement is found and enables comprehensive understanding of the dynamics of supermodes in oxide-confined coupled cavity VCSELs. article_number: '053102' author: - first_name: M. full_name: Lindemann, M. last_name: Lindemann - first_name: M. full_name: D’Alessandro, M. last_name: D’Alessandro - first_name: N. full_name: Ledentsov, N. last_name: Ledentsov - first_name: O. Y. full_name: Makarov, O. Y. last_name: Makarov - first_name: N. N. full_name: Ledentsov, N. N. last_name: Ledentsov - first_name: A. full_name: Tibaldi, A. last_name: Tibaldi - first_name: N. C. full_name: Gerhardt, N. C. last_name: Gerhardt - first_name: M. R. full_name: Hofmann, M. R. last_name: Hofmann citation: ama: Lindemann M, D’Alessandro M, Ledentsov N, et al. Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics. 2025;138(5). doi:10.1063/5.0275622 apa: Lindemann, M., D’Alessandro, M., Ledentsov, N., Makarov, O. Y., Ledentsov, N. N., Tibaldi, A., Gerhardt, N. C., & Hofmann, M. R. (2025). Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency. Journal of Applied Physics, 138(5), Article 053102. https://doi.org/10.1063/5.0275622 bibtex: '@article{Lindemann_D’Alessandro_Ledentsov_Makarov_Ledentsov_Tibaldi_Gerhardt_Hofmann_2025, title={Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency}, volume={138}, DOI={10.1063/5.0275622}, number={5053102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Lindemann, M. and D’Alessandro, M. and Ledentsov, N. and Makarov, O. Y. and Ledentsov, N. N. and Tibaldi, A. and Gerhardt, N. C. and Hofmann, M. R.}, year={2025} }' chicago: Lindemann, M., M. D’Alessandro, N. Ledentsov, O. Y. Makarov, N. N. Ledentsov, A. Tibaldi, N. C. Gerhardt, and M. R. Hofmann. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics 138, no. 5 (2025). https://doi.org/10.1063/5.0275622. ieee: 'M. Lindemann et al., “Laterally coupled vertical-cavity surface-emitting lasers with                    tunable resonance width and frequency,” Journal of Applied Physics, vol. 138, no. 5, Art. no. 053102, 2025, doi: 10.1063/5.0275622.' mla: Lindemann, M., et al. “Laterally Coupled Vertical-Cavity Surface-Emitting Lasers with                    Tunable Resonance Width and Frequency.” Journal of Applied Physics, vol. 138, no. 5, 053102, AIP Publishing, 2025, doi:10.1063/5.0275622. short: M. Lindemann, M. D’Alessandro, N. Ledentsov, O.Y. Makarov, N.N. Ledentsov, A. Tibaldi, N.C. Gerhardt, M.R. Hofmann, Journal of Applied Physics 138 (2025). date_created: 2025-10-23T11:16:04Z date_updated: 2025-10-23T11:16:21Z doi: 10.1063/5.0275622 intvolume: ' 138' issue: '5' language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Laterally coupled vertical-cavity surface-emitting lasers with tunable resonance width and frequency type: journal_article user_id: '15911' volume: 138 year: '2025' ... --- _id: '59269' abstract: - lang: eng text: Ferroelectric materials play a crucial role in a broad range of technologies due to their unique properties that are deeply connected to the pattern and behavior of their ferroelectric (FE) domains. Chief among them, barium titanate (BaTiO3; BTO) sees widespread applications such as in electronics but equally is a ferroelectric model system for fundamental research, e.g., to study the interplay of such FE domains, the domain walls (DWs), and their macroscopic properties, owed to BTO’s multiple and experimentally accessible phase transitions. Here, we employ Second Harmonic Generation Microscopy (SHGM) to in situ investigate the cubic-to-tetragonal (at ∼126°C) and the tetragonal-to-orthorhombic (at ∼5°C) phase transition in single-crystalline BTO via three-dimensional (3D) DW mapping. We demonstrate that SHGM imaging provides the direct visualization of FE domain switching as well as the domain dynamics in 3D, shedding light on the interplay of the domain structure and phase transition. These results allow us to extract the different transition temperatures locally, to unveil the hysteresis behavior, and to determine the type of phase transition at play (first/second order) from the recorded SHGM data. The capabilities of SHGM in uncovering these crucial phenomena can easily be applied to other ferroelectrics to provide new possibilities for in situ engineering of advanced ferroic devices. article_number: '154102' article_type: original author: - first_name: Benjamin full_name: Kirbus, Benjamin last_name: Kirbus - first_name: Samuel D. full_name: Seddon, Samuel D. last_name: Seddon - first_name: Iuliia full_name: Kiseleva, Iuliia last_name: Kiseleva - first_name: Elke full_name: Beyreuther, Elke last_name: Beyreuther - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng citation: ama: Kirbus B, Seddon SD, Kiseleva I, Beyreuther E, Rüsing M, Eng LM. Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy. Journal of Applied Physics. 2024;136(15). doi:10.1063/5.0237769 apa: Kirbus, B., Seddon, S. D., Kiseleva, I., Beyreuther, E., Rüsing, M., & Eng, L. M. (2024). Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy. Journal of Applied Physics, 136(15), Article 154102. https://doi.org/10.1063/5.0237769 bibtex: '@article{Kirbus_Seddon_Kiseleva_Beyreuther_Rüsing_Eng_2024, title={Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy}, volume={136}, DOI={10.1063/5.0237769}, number={15154102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Kirbus, Benjamin and Seddon, Samuel D. and Kiseleva, Iuliia and Beyreuther, Elke and Rüsing, Michael and Eng, Lukas M.}, year={2024} }' chicago: Kirbus, Benjamin, Samuel D. Seddon, Iuliia Kiseleva, Elke Beyreuther, Michael Rüsing, and Lukas M. Eng. “Probing Ferroelectric Phase Transitions in Barium Titanate Single Crystals via In-Situ Second Harmonic Generation Microscopy.” Journal of Applied Physics 136, no. 15 (2024). https://doi.org/10.1063/5.0237769. ieee: 'B. Kirbus, S. D. Seddon, I. Kiseleva, E. Beyreuther, M. Rüsing, and L. M. Eng, “Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy,” Journal of Applied Physics, vol. 136, no. 15, Art. no. 154102, 2024, doi: 10.1063/5.0237769.' mla: Kirbus, Benjamin, et al. “Probing Ferroelectric Phase Transitions in Barium Titanate Single Crystals via In-Situ Second Harmonic Generation Microscopy.” Journal of Applied Physics, vol. 136, no. 15, 154102, AIP Publishing, 2024, doi:10.1063/5.0237769. short: B. Kirbus, S.D. Seddon, I. Kiseleva, E. Beyreuther, M. Rüsing, L.M. Eng, Journal of Applied Physics 136 (2024). date_created: 2025-04-02T15:57:11Z date_updated: 2025-04-02T15:59:55Z department: - _id: '15' - _id: '623' - _id: '288' doi: 10.1063/5.0237769 intvolume: ' 136' issue: '15' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0237769' oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy type: journal_article user_id: '22501' volume: 136 year: '2024' ... --- _id: '59273' abstract: - lang: eng text: Ferroelectric domain walls (DWs) are promising structures for assembling future nano-electronic circuit elements on a larger scale since reporting domain wall currents of up to 1 mA per single DW. One key requirement hereto is their reproducible manufacturing by gaining preparative control over domain size and domain wall conductivity (DWC). To date, most works on DWC have focused on exploring the fundamental electrical properties of individual DWs within single-shot experiments, with an emphasis on quantifying the origins of DWC. Very few reports exist when it comes to comparing the DWC properties between two separate DWs, and literally nothing exists where issues of reproducibility in DWC devices have been addressed. To fill this gap while facing the challenge of finding guidelines for achieving predictable DWC performance, we report on a procedure that allows us to reproducibly prepare single hexagonal domains of a predefined diameter into uniaxial ferroelectric lithium niobate single crystals of 200 and 300 μm thickness, respectively. We show that the domain diameter can be controlled with an uncertainty of a few percent. As-grown DWs are then subjected to a standard procedure of current-limited high-voltage DWC enhancement, and they repetitively reach a DWC increase of six orders of magnitude. While all resulting DWs show significantly enhanced DWC values, their individual current–voltage (I–V) characteristics exhibit different shapes, which can be explained by variations in their 3D real structure reflecting local heterogeneities by defects, DW pinning, and surface-near DW inclination. article_type: original author: - first_name: Julius full_name: Ratzenberger, Julius last_name: Ratzenberger - first_name: Iuliia full_name: Kiseleva, Iuliia last_name: Kiseleva - first_name: Boris full_name: Koppitz, Boris last_name: Koppitz - first_name: Elke full_name: Beyreuther, Elke last_name: Beyreuther - first_name: Manuel full_name: Zahn, Manuel last_name: Zahn - first_name: Joshua full_name: Gössel, Joshua last_name: Gössel - first_name: Peter A. full_name: Hegarty, Peter A. last_name: Hegarty - first_name: Zeeshan H. full_name: Amber, Zeeshan H. last_name: Amber - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng citation: ama: Ratzenberger J, Kiseleva I, Koppitz B, et al. Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals. Journal of Applied Physics. 2024;136(10):104302. doi:10.1063/5.0219300 apa: Ratzenberger, J., Kiseleva, I., Koppitz, B., Beyreuther, E., Zahn, M., Gössel, J., Hegarty, P. A., Amber, Z. H., Rüsing, M., & Eng, L. M. (2024). Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals. Journal of Applied Physics, 136(10), 104302. https://doi.org/10.1063/5.0219300 bibtex: '@article{Ratzenberger_Kiseleva_Koppitz_Beyreuther_Zahn_Gössel_Hegarty_Amber_Rüsing_Eng_2024, title={Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals}, volume={136}, DOI={10.1063/5.0219300}, number={10}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Ratzenberger, Julius and Kiseleva, Iuliia and Koppitz, Boris and Beyreuther, Elke and Zahn, Manuel and Gössel, Joshua and Hegarty, Peter A. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}, year={2024}, pages={104302} }' chicago: 'Ratzenberger, Julius, Iuliia Kiseleva, Boris Koppitz, Elke Beyreuther, Manuel Zahn, Joshua Gössel, Peter A. Hegarty, Zeeshan H. Amber, Michael Rüsing, and Lukas M. Eng. “Toward the Reproducible Fabrication of Conductive Ferroelectric Domain Walls into Lithium Niobate Bulk Single Crystals.” Journal of Applied Physics 136, no. 10 (2024): 104302. https://doi.org/10.1063/5.0219300.' ieee: 'J. Ratzenberger et al., “Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals,” Journal of Applied Physics, vol. 136, no. 10, p. 104302, 2024, doi: 10.1063/5.0219300.' mla: Ratzenberger, Julius, et al. “Toward the Reproducible Fabrication of Conductive Ferroelectric Domain Walls into Lithium Niobate Bulk Single Crystals.” Journal of Applied Physics, vol. 136, no. 10, AIP Publishing, 2024, p. 104302, doi:10.1063/5.0219300. short: J. Ratzenberger, I. Kiseleva, B. Koppitz, E. Beyreuther, M. Zahn, J. Gössel, P.A. Hegarty, Z.H. Amber, M. Rüsing, L.M. Eng, Journal of Applied Physics 136 (2024) 104302. date_created: 2025-04-02T16:12:29Z date_updated: 2025-04-02T16:14:31Z department: - _id: '288' - _id: '15' - _id: '623' doi: 10.1063/5.0219300 intvolume: ' 136' issue: '10' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0219300' oa: '1' page: '104302' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals type: journal_article user_id: '22501' volume: 136 year: '2024' ... --- _id: '54966' abstract: - lang: eng text: Piezoresponse force microscopy (PFM) is one of the most widespread methods for investigating and visualizing ferroelectric domain structures down to the nanometer length scale. PFM makes use of the direct coupling of the piezoelectric response to the crystal lattice, and hence, it is most often applied to spatially map the three-dimensional (3D) near-surface domain distribution of any polar or ferroic sample. Nonetheless, since most samples investigated by PFM are at least semiconducting or fully insulating, the electric ac field emerging from the conductive scanning force microscopy (SFM) tip penetrates the sample and, hence, may also couple to polar features that are deeply buried into the bulk of the sample under investigation. Thus, in the work presented here, we experimentally and theoretically explore the contrast and depth resolution capabilities of PFM, by analyzing the dependence of several key parameters. These key parameters include the depth of the buried feature, i.e., here a domain wall (DW), as well as PFM-relevant technical parameters such as the tip radius, the PFM drive voltage and frequency, and the signal-to-noise ratio. The theoretical predictions are experimentally verified using x-cut periodically poled lithium niobate single crystals that are specially prepared into wedge-shaped samples, in order to allow the buried feature, here the DW, to be “positioned” at any depth into the bulk. This inspection essentially contributes to the fundamental understanding in PFM contrast analysis and to the reconstruction of 3D domain structures down to a 1 μm-penetration depth into the sample. article_type: original author: - first_name: Matthias full_name: Roeper, Matthias last_name: Roeper - first_name: Samuel D. full_name: Seddon, Samuel D. last_name: Seddon - first_name: Zeeshan H. full_name: Amber, Zeeshan H. last_name: Amber - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng citation: ama: Roeper M, Seddon SD, Amber ZH, Rüsing M, Eng LM. Depth resolution in piezoresponse force microscopy. Journal of Applied Physics. 2024;135(22). doi:10.1063/5.0206784 apa: Roeper, M., Seddon, S. D., Amber, Z. H., Rüsing, M., & Eng, L. M. (2024). Depth resolution in piezoresponse force microscopy. Journal of Applied Physics, 135(22). https://doi.org/10.1063/5.0206784 bibtex: '@article{Roeper_Seddon_Amber_Rüsing_Eng_2024, title={Depth resolution in piezoresponse force microscopy}, volume={135}, DOI={10.1063/5.0206784}, number={22}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Roeper, Matthias and Seddon, Samuel D. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}, year={2024} }' chicago: Roeper, Matthias, Samuel D. Seddon, Zeeshan H. Amber, Michael Rüsing, and Lukas M. Eng. “Depth Resolution in Piezoresponse Force Microscopy.” Journal of Applied Physics 135, no. 22 (2024). https://doi.org/10.1063/5.0206784. ieee: 'M. Roeper, S. D. Seddon, Z. H. Amber, M. Rüsing, and L. M. Eng, “Depth resolution in piezoresponse force microscopy,” Journal of Applied Physics, vol. 135, no. 22, 2024, doi: 10.1063/5.0206784.' mla: Roeper, Matthias, et al. “Depth Resolution in Piezoresponse Force Microscopy.” Journal of Applied Physics, vol. 135, no. 22, AIP Publishing, 2024, doi:10.1063/5.0206784. short: M. Roeper, S.D. Seddon, Z.H. Amber, M. Rüsing, L.M. Eng, Journal of Applied Physics 135 (2024). date_created: 2024-07-01T21:00:43Z date_updated: 2025-04-03T12:35:34Z department: - _id: '15' - _id: '169' - _id: '288' - _id: '623' doi: 10.1063/5.0206784 intvolume: ' 135' issue: '22' keyword: - Ferroelectrics - lithium niobate - piezoresponse force microscopy language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1063/5.0206784 oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Depth resolution in piezoresponse force microscopy type: journal_article user_id: '22501' volume: 135 year: '2024' ... --- _id: '47994' abstract: - lang: eng text: Coherent nonlinear optical μ-spectroscopy is a frequently used tool in modern material science as it is sensitive to many different local observables, which comprise, among others, crystal symmetry and vibrational properties. The richness in information, however, may come with challenges in data interpretation, as one has to disentangle the many different effects like multiple reflections, phase jumps at interfaces, or the influence of the Guoy-phase. In order to facilitate interpretation, the work presented here proposes an easy-to-use semi-analytical modeling Ansatz, which bases upon known analytical solutions using Gaussian beams. Specifically, we apply this Ansatz to compute nonlinear optical responses of (thin film) optical materials. We try to conserve the meaning of intuitive parameters like the Gouy-phase and the nonlinear coherent interaction length. In particular, the concept of coherence length is extended, which is a must when using focal beams. The model is subsequently applied to exemplary cases of second- and third-harmonic generation. We observe a very good agreement with experimental data, and furthermore, despite the constraints and limits of the analytical Ansatz, our model performs similarly well as when using more rigorous simulations. However, it outperforms the latter in terms of computational power, requiring more than three orders less computational time and less performant computer systems. article_number: '123105' article_type: original author: - first_name: Kai J. full_name: Spychala, Kai J. last_name: Spychala - first_name: Zeeshan H. full_name: Amber, Zeeshan H. last_name: Amber - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 citation: ama: 'Spychala KJ, Amber ZH, Eng LM, Rüsing M. Modeling nonlinear optical interactions of focused beams in bulk crystals and thin films: A phenomenological approach. Journal of Applied Physics. 2023;133(12). doi:10.1063/5.0136252' apa: 'Spychala, K. J., Amber, Z. H., Eng, L. M., & Rüsing, M. (2023). Modeling nonlinear optical interactions of focused beams in bulk crystals and thin films: A phenomenological approach. Journal of Applied Physics, 133(12), Article 123105. https://doi.org/10.1063/5.0136252' bibtex: '@article{Spychala_Amber_Eng_Rüsing_2023, title={Modeling nonlinear optical interactions of focused beams in bulk crystals and thin films: A phenomenological approach}, volume={133}, DOI={10.1063/5.0136252}, number={12123105}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Spychala, Kai J. and Amber, Zeeshan H. and Eng, Lukas M. and Rüsing, Michael}, year={2023} }' chicago: 'Spychala, Kai J., Zeeshan H. Amber, Lukas M. Eng, and Michael Rüsing. “Modeling Nonlinear Optical Interactions of Focused Beams in Bulk Crystals and Thin Films: A Phenomenological Approach.” Journal of Applied Physics 133, no. 12 (2023). https://doi.org/10.1063/5.0136252.' ieee: 'K. J. Spychala, Z. H. Amber, L. M. Eng, and M. Rüsing, “Modeling nonlinear optical interactions of focused beams in bulk crystals and thin films: A phenomenological approach,” Journal of Applied Physics, vol. 133, no. 12, Art. no. 123105, 2023, doi: 10.1063/5.0136252.' mla: 'Spychala, Kai J., et al. “Modeling Nonlinear Optical Interactions of Focused Beams in Bulk Crystals and Thin Films: A Phenomenological Approach.” Journal of Applied Physics, vol. 133, no. 12, 123105, AIP Publishing, 2023, doi:10.1063/5.0136252.' short: K.J. Spychala, Z.H. Amber, L.M. Eng, M. Rüsing, Journal of Applied Physics 133 (2023). date_created: 2023-10-11T09:09:00Z date_updated: 2023-10-11T16:10:54Z doi: 10.1063/5.0136252 extern: '1' intvolume: ' 133' issue: '12' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0136252' oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: 'Modeling nonlinear optical interactions of focused beams in bulk crystals and thin films: A phenomenological approach' type: journal_article user_id: '22501' volume: 133 year: '2023' ... --- _id: '46573' abstract: - lang: eng text: 'An ultra-fast change of the absorption onset for zincblende gallium-nitride (zb-GaN) (fundamental bandgap: 3.23 eV) is observed by investigating the imaginary part of the dielectric function using time-dependent femtosecond pump–probe spectroscopic ellipsometry between 2.9 and 3.7 eV. The 266 nm (4.66 eV) pump pulses induce a large electron–hole pair concentration up to 4×1020cm−3, which shift the transition energy between conduction and valence bands due to many-body effects up to ≈500 meV. Here, the absorption onset increases due to band filling while the bandgap renormalization at the same time decreases the bandgap. Additionally, the absorption of the pump-beam creates a free-carrier profile within the 605 nm zb-GaN layer with high free-carrier concentrations at the surface, and low concentrations at the interface to the substrate. This leads to varying optical properties from the sample surface (high transition energy) to substrate (low transition energy), which are taken into account by grading analysis for an accurate description of the experimental data. For this, a model describing the time- and position-dependent free-carrier concentration is formulated by considering the relaxation, recombination, and diffusion of those carriers. We provide a quantitative analysis of optical experimental data (ellipsometric angles Ψ and Δ) as well as a plot for the time-dependent change of the imaginary part of the dielectric function.' author: - first_name: Elias full_name: Baron, Elias last_name: Baron - first_name: Rüdiger full_name: Goldhahn, Rüdiger last_name: Goldhahn - first_name: Shirly full_name: Espinoza, Shirly last_name: Espinoza - first_name: Martin full_name: Zahradník, Martin last_name: Zahradník - first_name: Mateusz full_name: Rebarz, Mateusz last_name: Rebarz - first_name: Jakob full_name: Andreasson, Jakob last_name: Andreasson - first_name: Michael full_name: Deppe, Michael last_name: Deppe - first_name: Donat Josef full_name: As, Donat Josef id: '14' last_name: As orcid: 0000-0003-1121-3565 - first_name: Martin full_name: Feneberg, Martin last_name: Feneberg citation: ama: Baron E, Goldhahn R, Espinoza S, et al. Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function. Journal of Applied Physics. 2023;134(7). doi:10.1063/5.0153091 apa: Baron, E., Goldhahn, R., Espinoza, S., Zahradník, M., Rebarz, M., Andreasson, J., Deppe, M., As, D. J., & Feneberg, M. (2023). Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function. Journal of Applied Physics, 134(7). https://doi.org/10.1063/5.0153091 bibtex: '@article{Baron_Goldhahn_Espinoza_Zahradník_Rebarz_Andreasson_Deppe_As_Feneberg_2023, title={Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function}, volume={134}, DOI={10.1063/5.0153091}, number={7}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Baron, Elias and Goldhahn, Rüdiger and Espinoza, Shirly and Zahradník, Martin and Rebarz, Mateusz and Andreasson, Jakob and Deppe, Michael and As, Donat Josef and Feneberg, Martin}, year={2023} }' chicago: Baron, Elias, Rüdiger Goldhahn, Shirly Espinoza, Martin Zahradník, Mateusz Rebarz, Jakob Andreasson, Michael Deppe, Donat Josef As, and Martin Feneberg. “Time-Resolved Pump–Probe Spectroscopic Ellipsometry of Cubic GaN. I. Determination of the Dielectric Function.” Journal of Applied Physics 134, no. 7 (2023). https://doi.org/10.1063/5.0153091. ieee: 'E. Baron et al., “Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function,” Journal of Applied Physics, vol. 134, no. 7, 2023, doi: 10.1063/5.0153091.' mla: Baron, Elias, et al. “Time-Resolved Pump–Probe Spectroscopic Ellipsometry of Cubic GaN. I. Determination of the Dielectric Function.” Journal of Applied Physics, vol. 134, no. 7, AIP Publishing, 2023, doi:10.1063/5.0153091. short: E. Baron, R. Goldhahn, S. Espinoza, M. Zahradník, M. Rebarz, J. Andreasson, M. Deppe, D.J. As, M. Feneberg, Journal of Applied Physics 134 (2023). date_created: 2023-08-18T08:17:41Z date_updated: 2023-10-09T09:17:15Z department: - _id: '15' - _id: '230' doi: 10.1063/5.0153091 intvolume: ' 134' issue: '7' keyword: - General Physics and Astronomy language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function type: journal_article user_id: '14931' volume: 134 year: '2023' ... --- _id: '54853' abstract: - lang: eng text: The nitrogen-vacancy (NV) centers (NCVSi)− in 4H silicon carbide (SiC) constitute an ensemble of spin S = 1 solid state qubits interacting with the surrounding 14N and 29Si nuclei. As quantum applications based on a polarization transfer from the electron spin to the nuclei require the knowledge of the electron–nuclear interaction parameters, we have used high-frequency (94 GHz) electron–nuclear double resonance spectroscopy combined with first-principles density functional theory to investigate the hyperfine and nuclear quadrupole interactions of the basal and axial NV centers. We observed that the four inequivalent NV configurations (hk, kh, hh, and kk) exhibit different electron–nuclear interaction parameters, suggesting that each NV center may act as a separate optically addressable qubit. Finally, we rationalized the observed differences in terms of distinctions in the local atomic structures of the NV configurations. Thus, our results provide the basic knowledge for an extension of quantum protocols involving the 14N nuclear spin. author: - first_name: F. F. full_name: Murzakhanov, F. F. last_name: Murzakhanov - first_name: M. A. full_name: Sadovnikova, M. A. last_name: Sadovnikova - first_name: G. V. full_name: Mamin, G. V. last_name: Mamin - first_name: S. S. full_name: Nagalyuk, S. S. last_name: Nagalyuk - first_name: H. J. full_name: von Bardeleben, H. J. last_name: von Bardeleben - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Timur full_name: Biktagirov, Timur id: '65612' last_name: Biktagirov - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: V. A. full_name: Soltamov, V. A. last_name: Soltamov citation: ama: 'Murzakhanov FF, Sadovnikova MA, Mamin GV, et al. 14N Hyperfine and nuclear interactions of axial and basal NV centers in 4H-SiC: A high frequency (94 GHz) ENDOR study. Journal of Applied Physics. 2023;134(12). doi:10.1063/5.0170099' apa: 'Murzakhanov, F. F., Sadovnikova, M. A., Mamin, G. V., Nagalyuk, S. S., von Bardeleben, H. J., Schmidt, W. G., Biktagirov, T., Gerstmann, U., & Soltamov, V. A. (2023). 14N Hyperfine and nuclear interactions of axial and basal NV centers in 4H-SiC: A high frequency (94 GHz) ENDOR study. Journal of Applied Physics, 134(12). https://doi.org/10.1063/5.0170099' bibtex: '@article{Murzakhanov_Sadovnikova_Mamin_Nagalyuk_von Bardeleben_Schmidt_Biktagirov_Gerstmann_Soltamov_2023, title={14N Hyperfine and nuclear interactions of axial and basal NV centers in 4H-SiC: A high frequency (94 GHz) ENDOR study}, volume={134}, DOI={10.1063/5.0170099}, number={12}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Murzakhanov, F. F. and Sadovnikova, M. A. and Mamin, G. V. and Nagalyuk, S. S. and von Bardeleben, H. J. and Schmidt, Wolf Gero and Biktagirov, Timur and Gerstmann, Uwe and Soltamov, V. A.}, year={2023} }' chicago: 'Murzakhanov, F. F., M. A. Sadovnikova, G. V. Mamin, S. S. Nagalyuk, H. J. von Bardeleben, Wolf Gero Schmidt, Timur Biktagirov, Uwe Gerstmann, and V. A. Soltamov. “14N Hyperfine and Nuclear Interactions of Axial and Basal NV Centers in 4H-SiC: A High Frequency (94 GHz) ENDOR Study.” Journal of Applied Physics 134, no. 12 (2023). https://doi.org/10.1063/5.0170099.' ieee: 'F. F. Murzakhanov et al., “14N Hyperfine and nuclear interactions of axial and basal NV centers in 4H-SiC: A high frequency (94 GHz) ENDOR study,” Journal of Applied Physics, vol. 134, no. 12, 2023, doi: 10.1063/5.0170099.' mla: 'Murzakhanov, F. F., et al. “14N Hyperfine and Nuclear Interactions of Axial and Basal NV Centers in 4H-SiC: A High Frequency (94 GHz) ENDOR Study.” Journal of Applied Physics, vol. 134, no. 12, AIP Publishing, 2023, doi:10.1063/5.0170099.' short: F.F. Murzakhanov, M.A. Sadovnikova, G.V. Mamin, S.S. Nagalyuk, H.J. von Bardeleben, W.G. Schmidt, T. Biktagirov, U. Gerstmann, V.A. Soltamov, Journal of Applied Physics 134 (2023). date_created: 2024-06-24T06:18:17Z date_updated: 2024-06-24T06:30:19Z department: - _id: '15' - _id: '170' - _id: '295' - _id: '790' - _id: '27' - _id: '230' doi: 10.1063/5.0170099 intvolume: ' 134' issue: '12' language: - iso: eng project: - _id: '52' name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: '14N Hyperfine and nuclear interactions of axial and basal NV centers in 4H-SiC: A high frequency (94 GHz) ENDOR study' type: journal_article user_id: '16199' volume: 134 year: '2023' ... --- _id: '34056' abstract: - lang: eng text: ' A process sequence enabling the large-area fabrication of nanopillar-patterned semiconductor templates for selective-area heteroepitaxy is developed. Herein, the nanopillar tops surrounded by a SiNx mask film serve as nanoscale growth areas. The molecular beam epitaxial growth of InAs on such patterned GaAs[Formula: see text]A templates is investigated by means of electron microscopy. It is found that defect-free nanoscale InAs islands grow selectively on the nanopillar tops at a substrate temperature of 425 °C. High-angle annular dark-field scanning transmission electron microscopy imaging reveals that for a growth temperature of 400 °C, the InAs islands show a tendency to form wurtzite phase arms extending along the lateral [Formula: see text] directions from the central zinc blende region of the islands. This is ascribed to a temporary self-catalyzed vapor–liquid–solid growth on [Formula: see text] B facets, which leads to a kinetically induced preference for the nucleation of the wurtzite phase driven by the local, instantaneous V/III ratio, and to a concomitant reduction of surface energy of the nanoscale diameter arms. ' article_number: '185701' author: - first_name: Thomas full_name: Riedl, Thomas id: '36950' last_name: Riedl - first_name: Vinay S. full_name: Kunnathully, Vinay S. last_name: Kunnathully - first_name: Akshay Kumar full_name: Verma, Akshay Kumar id: '72998' last_name: Verma - first_name: Timo full_name: Langer, Timo last_name: Langer - first_name: Dirk full_name: Reuter, Dirk id: '37763' last_name: Reuter - first_name: Björn full_name: Büker, Björn last_name: Büker - first_name: Andreas full_name: Hütten, Andreas last_name: Hütten - first_name: Jörg full_name: Lindner, Jörg id: '20797' last_name: Lindner citation: ama: Riedl T, Kunnathully VS, Verma AK, et al. Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A. Journal of Applied Physics. 2022;132(18). doi:10.1063/5.0121559 apa: Riedl, T., Kunnathully, V. S., Verma, A. K., Langer, T., Reuter, D., Büker, B., Hütten, A., & Lindner, J. (2022). Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A. Journal of Applied Physics, 132(18), Article 185701. https://doi.org/10.1063/5.0121559 bibtex: '@article{Riedl_Kunnathully_Verma_Langer_Reuter_Büker_Hütten_Lindner_2022, title={Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A}, volume={132}, DOI={10.1063/5.0121559}, number={18185701}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Riedl, Thomas and Kunnathully, Vinay S. and Verma, Akshay Kumar and Langer, Timo and Reuter, Dirk and Büker, Björn and Hütten, Andreas and Lindner, Jörg}, year={2022} }' chicago: Riedl, Thomas, Vinay S. Kunnathully, Akshay Kumar Verma, Timo Langer, Dirk Reuter, Björn Büker, Andreas Hütten, and Jörg Lindner. “Selective Area Heteroepitaxy of InAs Nanostructures on Nanopillar-Patterned GaAs(111)A.” Journal of Applied Physics 132, no. 18 (2022). https://doi.org/10.1063/5.0121559. ieee: 'T. Riedl et al., “Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A,” Journal of Applied Physics, vol. 132, no. 18, Art. no. 185701, 2022, doi: 10.1063/5.0121559.' mla: Riedl, Thomas, et al. “Selective Area Heteroepitaxy of InAs Nanostructures on Nanopillar-Patterned GaAs(111)A.” Journal of Applied Physics, vol. 132, no. 18, 185701, AIP Publishing, 2022, doi:10.1063/5.0121559. short: T. Riedl, V.S. Kunnathully, A.K. Verma, T. Langer, D. Reuter, B. Büker, A. Hütten, J. Lindner, Journal of Applied Physics 132 (2022). date_created: 2022-11-10T14:19:21Z date_updated: 2023-01-10T12:08:26Z department: - _id: '15' - _id: '230' doi: 10.1063/5.0121559 intvolume: ' 132' issue: '18' keyword: - General Physics and Astronomy language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A type: journal_article user_id: '77496' volume: 132 year: '2022' ... --- _id: '47984' abstract: - lang: eng text: Recent analyses by polarization resolved second-harmonic (SH) microscopy have demonstrated that ferroelectric (FE) domain walls (DWs) can possess non-Ising wall characteristics and topological nature. These analyses rely on locally analyzing the properties, directionality, and magnitude of the second-order nonlinear tensor. However, when inspecting FE DWs with SH microscopy, a manifold of different effects may contribute to the observed signal difference between domains and DWs, i.e., far-field interference, Čerenkov-type phase-matching (CSHG), and changes in the aforementioned local nonlinear optical properties. They all might be present at the same time and, therefore, require careful interpretation and separation. In this work, we demonstrate how the particularly strong Čerenkov-type contrast can selectively be blocked using dark- and bright-field SH microscopy. Based on this approach, we show that other contrast mechanisms emerge that were previously overlayed by CSHG but can now be readily selected through the appropriate experimental geometry. Using the methods presented, we show that the strength of the CSHG contrast compared to the other mechanisms is approximately 22 times higher. This work lays the foundation for the in-depth analysis of FE DW topologies by SH microscopy. article_type: original author: - first_name: Peter A. full_name: Hegarty, Peter A. last_name: Hegarty - first_name: Henrik full_name: Beccard, Henrik last_name: Beccard - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 citation: ama: 'Hegarty PA, Beccard H, Eng LM, Rüsing M. Turn all the lights off: Bright- and dark-field second-harmonic microscopy to select contrast mechanisms for ferroelectric domain walls. Journal of Applied Physics. 2022;131(24). doi:10.1063/5.0094988' apa: 'Hegarty, P. A., Beccard, H., Eng, L. M., & Rüsing, M. (2022). Turn all the lights off: Bright- and dark-field second-harmonic microscopy to select contrast mechanisms for ferroelectric domain walls. Journal of Applied Physics, 131(24). https://doi.org/10.1063/5.0094988' bibtex: '@article{Hegarty_Beccard_Eng_Rüsing_2022, title={Turn all the lights off: Bright- and dark-field second-harmonic microscopy to select contrast mechanisms for ferroelectric domain walls}, volume={131}, DOI={10.1063/5.0094988}, number={24}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Hegarty, Peter A. and Beccard, Henrik and Eng, Lukas M. and Rüsing, Michael}, year={2022} }' chicago: 'Hegarty, Peter A., Henrik Beccard, Lukas M. Eng, and Michael Rüsing. “Turn All the Lights off: Bright- and Dark-Field Second-Harmonic Microscopy to Select Contrast Mechanisms for Ferroelectric Domain Walls.” Journal of Applied Physics 131, no. 24 (2022). https://doi.org/10.1063/5.0094988.' ieee: 'P. A. Hegarty, H. Beccard, L. M. Eng, and M. Rüsing, “Turn all the lights off: Bright- and dark-field second-harmonic microscopy to select contrast mechanisms for ferroelectric domain walls,” Journal of Applied Physics, vol. 131, no. 24, 2022, doi: 10.1063/5.0094988.' mla: 'Hegarty, Peter A., et al. “Turn All the Lights off: Bright- and Dark-Field Second-Harmonic Microscopy to Select Contrast Mechanisms for Ferroelectric Domain Walls.” Journal of Applied Physics, vol. 131, no. 24, AIP Publishing, 2022, doi:10.1063/5.0094988.' short: P.A. Hegarty, H. Beccard, L.M. Eng, M. Rüsing, Journal of Applied Physics 131 (2022). date_created: 2023-10-11T08:53:25Z date_updated: 2023-10-11T08:53:55Z doi: 10.1063/5.0094988 extern: '1' funded_apc: '1' intvolume: ' 131' issue: '24' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0094988' oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: 'Turn all the lights off: Bright- and dark-field second-harmonic microscopy to select contrast mechanisms for ferroelectric domain walls' type: journal_article user_id: '22501' volume: 131 year: '2022' ... --- _id: '47989' abstract: - lang: eng text: Thin-film materials from μm thickness down to single-atomic-layered 2D materials play a central role in many novel electronic and optical applications. Coherent, nonlinear optical (NLO) μ-spectroscopy offers insight into the local thickness, stacking order, symmetry, or electronic and vibrational properties. Thin films and 2D materials are usually supported on multi-layered substrates leading to (multi-)reflections, interference, or phase jumps at interfaces during μ-spectroscopy, which all can make the interpretation of experiments particularly challenging. The disentanglement of the influence parameters can be achieved via rigorous theoretical analysis. In this work, we compare two self-developed modeling approaches, a semi-analytical and a fully vectorial model, to experiments carried out in thin-film geometry for two archetypal NLO processes, second-harmonic and third-harmonic generation. In particular, we demonstrate that thin-film interference and phase matching do heavily influence the signal strength. Furthermore, we work out key differences between three and four photon processes, such as the role of the Gouy-phase shift and the focal position. Last, we can show that a relatively simple semi-analytical model, despite its limitations, is able to accurately describe experiments at a significantly lower computational cost as compared to a full vectorial modeling. This study lays the groundwork for performing quantitative NLO μ-spectroscopy on thin films and 2D materials, as it identifies and quantifies the impact of the corresponding sample and setup parameters on the NLO signal, in order to distinguish them from genuine material properties.< article_number: '213102' article_type: original author: - first_name: Zeeshan H. full_name: Amber, Zeeshan H. last_name: Amber - first_name: Kai J. full_name: Spychala, Kai J. last_name: Spychala - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 citation: ama: Amber ZH, Spychala KJ, Eng LM, Rüsing M. Nonlinear optical interactions in focused beams and nanosized structures. Journal of Applied Physics. 2022;132(21). doi:10.1063/5.0125926 apa: Amber, Z. H., Spychala, K. J., Eng, L. M., & Rüsing, M. (2022). Nonlinear optical interactions in focused beams and nanosized structures. Journal of Applied Physics, 132(21), Article 213102. https://doi.org/10.1063/5.0125926 bibtex: '@article{Amber_Spychala_Eng_Rüsing_2022, title={Nonlinear optical interactions in focused beams and nanosized structures}, volume={132}, DOI={10.1063/5.0125926}, number={21213102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Amber, Zeeshan H. and Spychala, Kai J. and Eng, Lukas M. and Rüsing, Michael}, year={2022} }' chicago: Amber, Zeeshan H., Kai J. Spychala, Lukas M. Eng, and Michael Rüsing. “Nonlinear Optical Interactions in Focused Beams and Nanosized Structures.” Journal of Applied Physics 132, no. 21 (2022). https://doi.org/10.1063/5.0125926. ieee: 'Z. H. Amber, K. J. Spychala, L. M. Eng, and M. Rüsing, “Nonlinear optical interactions in focused beams and nanosized structures,” Journal of Applied Physics, vol. 132, no. 21, Art. no. 213102, 2022, doi: 10.1063/5.0125926.' mla: Amber, Zeeshan H., et al. “Nonlinear Optical Interactions in Focused Beams and Nanosized Structures.” Journal of Applied Physics, vol. 132, no. 21, 213102, AIP Publishing, 2022, doi:10.1063/5.0125926. short: Z.H. Amber, K.J. Spychala, L.M. Eng, M. Rüsing, Journal of Applied Physics 132 (2022). date_created: 2023-10-11T08:59:23Z date_updated: 2023-10-11T09:01:37Z doi: 10.1063/5.0125926 funded_apc: '1' intvolume: ' 132' issue: '21' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0125926' oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Nonlinear optical interactions in focused beams and nanosized structures type: journal_article user_id: '22501' volume: 132 year: '2022' ... --- _id: '47988' abstract: - lang: eng text: Second harmonic (SH) microscopy represents a powerful tool for the investigation of crystalline systems, such as ferroelectrics and their domain walls (DWs). Under the condition of normal dispersion, i.e., the refractive index at the SH wavelength is larger as compared to the refractive index at the fundamental wavelength, n(2ω)>n(ω), bulk crystals will generate no SH signal. Should the bulk, however, contain DWs, an appreciable SH signal will still be detectable at the location of DWs stemming from the Čerenkov mechanism. In this work, we demonstrate both how SH signals are generated in bulk media and how the Čerenkov mechanism can be inhibited by using anomalous dispersion, i.e., n(ω)Journal of Applied Physics. 2022;132(21):214102. doi:10.1063/5.0115673 apa: Hegarty, P. A., Eng, L. M., & Rüsing, M. (2022). Tuning the Čerenkov second harmonic contrast from ferroelectric domain walls via anomalous dispersion. Journal of Applied Physics, 132(21), 214102. https://doi.org/10.1063/5.0115673 bibtex: '@article{Hegarty_Eng_Rüsing_2022, title={Tuning the Čerenkov second harmonic contrast from ferroelectric domain walls via anomalous dispersion}, volume={132}, DOI={10.1063/5.0115673}, number={21}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Hegarty, Peter A. and Eng, Lukas M. and Rüsing, Michael}, year={2022}, pages={214102} }' chicago: 'Hegarty, Peter A., Lukas M. Eng, and Michael Rüsing. “Tuning the Čerenkov Second Harmonic Contrast from Ferroelectric Domain Walls via Anomalous Dispersion.” Journal of Applied Physics 132, no. 21 (2022): 214102. https://doi.org/10.1063/5.0115673.' ieee: 'P. A. Hegarty, L. M. Eng, and M. Rüsing, “Tuning the Čerenkov second harmonic contrast from ferroelectric domain walls via anomalous dispersion,” Journal of Applied Physics, vol. 132, no. 21, p. 214102, 2022, doi: 10.1063/5.0115673.' mla: Hegarty, Peter A., et al. “Tuning the Čerenkov Second Harmonic Contrast from Ferroelectric Domain Walls via Anomalous Dispersion.” Journal of Applied Physics, vol. 132, no. 21, AIP Publishing, 2022, p. 214102, doi:10.1063/5.0115673. short: P.A. Hegarty, L.M. Eng, M. Rüsing, Journal of Applied Physics 132 (2022) 214102. date_created: 2023-10-11T08:57:55Z date_updated: 2023-10-11T08:58:50Z doi: 10.1063/5.0115673 extern: '1' funded_apc: '1' intvolume: ' 132' issue: '21' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.1063/5.0115673' oa: '1' page: '214102' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Tuning the Čerenkov second harmonic contrast from ferroelectric domain walls via anomalous dispersion type: journal_article user_id: '22501' volume: 132 year: '2022' ... --- _id: '47973' abstract: - lang: eng text: Thin-film lithium niobate (TFLN) in the form of x- or z-cut lithium-niobate-on-insulator has attracted considerable interest as a very promising and novel platform for developing integrated optoelectronic (nano)devices and exploring fundamental research. Here, we investigate the coherent interaction length lc of optical second-harmonic generation (SHG) microscopy in such samples, that are purposely prepared into a wedge shape, in order to elegantly tune the geometrical confinement from bulk thicknesses down to approximately 50 nm. SHG microscopy is a very powerful and non-invasive tool for the investigation of structural properties in the biological and solid-state sciences, especially for visualizing and analyzing ferroelectric domains and domain walls. However, unlike in bulk lithium niobate (LN), SHG microscopy in TFLN is impacted by interfacial reflections and resonant enhancement, both of which rely on film thickness and substrate material. In this paper, we show that the dominant SHG contribution measured on TFLN in backreflection is the co-propagating phase-matched SHG signal and not the counter-propagating SHG portion as is the case for bulk LN samples. Moreover, lc depends on the incident pump laser wavelength (sample dispersion) but also on the numerical aperture of the focussing objective in use. These experimental findings on x- and z-cut TFLN are excellently backed up by our advanced numerical simulations. article_type: original author: - first_name: Zeeshan H. full_name: Amber, Zeeshan H. last_name: Amber - first_name: Benjamin full_name: Kirbus, Benjamin last_name: Kirbus - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 citation: ama: Amber ZH, Kirbus B, Eng LM, Rüsing M. Quantifying the coherent interaction length of second-harmonic microscopy in lithium niobate confined nanostructures. Journal of Applied Physics. 2021;130(13):133102. doi:10.1063/5.0058996 apa: Amber, Z. H., Kirbus, B., Eng, L. M., & Rüsing, M. (2021). Quantifying the coherent interaction length of second-harmonic microscopy in lithium niobate confined nanostructures. Journal of Applied Physics, 130(13), 133102. https://doi.org/10.1063/5.0058996 bibtex: '@article{Amber_Kirbus_Eng_Rüsing_2021, title={Quantifying the coherent interaction length of second-harmonic microscopy in lithium niobate confined nanostructures}, volume={130}, DOI={10.1063/5.0058996}, number={13}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Amber, Zeeshan H. and Kirbus, Benjamin and Eng, Lukas M. and Rüsing, Michael}, year={2021}, pages={133102} }' chicago: 'Amber, Zeeshan H., Benjamin Kirbus, Lukas M. Eng, and Michael Rüsing. “Quantifying the Coherent Interaction Length of Second-Harmonic Microscopy in Lithium Niobate Confined Nanostructures.” Journal of Applied Physics 130, no. 13 (2021): 133102. https://doi.org/10.1063/5.0058996.' ieee: 'Z. H. Amber, B. Kirbus, L. M. Eng, and M. Rüsing, “Quantifying the coherent interaction length of second-harmonic microscopy in lithium niobate confined nanostructures,” Journal of Applied Physics, vol. 130, no. 13, p. 133102, 2021, doi: 10.1063/5.0058996.' mla: Amber, Zeeshan H., et al. “Quantifying the Coherent Interaction Length of Second-Harmonic Microscopy in Lithium Niobate Confined Nanostructures.” Journal of Applied Physics, vol. 130, no. 13, AIP Publishing, 2021, p. 133102, doi:10.1063/5.0058996. short: Z.H. Amber, B. Kirbus, L.M. Eng, M. Rüsing, Journal of Applied Physics 130 (2021) 133102. date_created: 2023-10-11T08:29:03Z date_updated: 2023-10-11T08:29:44Z doi: 10.1063/5.0058996 extern: '1' intvolume: ' 130' issue: '13' keyword: - General Physics and Astronomy language: - iso: eng page: '133102' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Quantifying the coherent interaction length of second-harmonic microscopy in lithium niobate confined nanostructures type: journal_article user_id: '22501' volume: 130 year: '2021' ... --- _id: '46011' article_number: '014102' author: - first_name: Dawei full_name: Zhang, Dawei last_name: Zhang - first_name: Daniel full_name: Sando, Daniel last_name: Sando - first_name: Ying full_name: Pan, Ying id: '100383' last_name: Pan - first_name: Pankaj full_name: Sharma, Pankaj last_name: Sharma - first_name: Jan full_name: Seidel, Jan last_name: Seidel citation: ama: Zhang D, Sando D, Pan Y, Sharma P, Seidel J. Robust ferroelectric polarization retention in harsh environments through engineered domain wall pinning. Journal of Applied Physics. 2021;129(1). doi:10.1063/5.0029620 apa: Zhang, D., Sando, D., Pan, Y., Sharma, P., & Seidel, J. (2021). Robust ferroelectric polarization retention in harsh environments through engineered domain wall pinning. Journal of Applied Physics, 129(1), Article 014102. https://doi.org/10.1063/5.0029620 bibtex: '@article{Zhang_Sando_Pan_Sharma_Seidel_2021, title={Robust ferroelectric polarization retention in harsh environments through engineered domain wall pinning}, volume={129}, DOI={10.1063/5.0029620}, number={1014102}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Zhang, Dawei and Sando, Daniel and Pan, Ying and Sharma, Pankaj and Seidel, Jan}, year={2021} }' chicago: Zhang, Dawei, Daniel Sando, Ying Pan, Pankaj Sharma, and Jan Seidel. “Robust Ferroelectric Polarization Retention in Harsh Environments through Engineered Domain Wall Pinning.” Journal of Applied Physics 129, no. 1 (2021). https://doi.org/10.1063/5.0029620. ieee: 'D. Zhang, D. Sando, Y. Pan, P. Sharma, and J. Seidel, “Robust ferroelectric polarization retention in harsh environments through engineered domain wall pinning,” Journal of Applied Physics, vol. 129, no. 1, Art. no. 014102, 2021, doi: 10.1063/5.0029620.' mla: Zhang, Dawei, et al. “Robust Ferroelectric Polarization Retention in Harsh Environments through Engineered Domain Wall Pinning.” Journal of Applied Physics, vol. 129, no. 1, 014102, AIP Publishing, 2021, doi:10.1063/5.0029620. short: D. Zhang, D. Sando, Y. Pan, P. Sharma, J. Seidel, Journal of Applied Physics 129 (2021). date_created: 2023-07-11T14:50:35Z date_updated: 2023-07-11T16:39:06Z doi: 10.1063/5.0029620 extern: '1' intvolume: ' 129' issue: '1' keyword: - General Physics and Astronomy language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Robust ferroelectric polarization retention in harsh environments through engineered domain wall pinning type: journal_article user_id: '100383' volume: 129 year: '2021' ... --- _id: '20644' abstract: - lang: eng text: Plasmonic nanoantennas for visible and infrared radiation strongly improve the interaction of light with the matter on the nanoscale due to their strong near-field enhancement. In this study, we investigate a double-resonant plasmonic nanoantenna, which makes use of plasmonic field enhancement, enhanced outcoupling of second harmonic light, and resonant lattice effects. Using this design, we demonstrate how the efficiency of second harmonic generation can be increased significantly by fully embedding the nanoantennas into nonlinear dielectric material ZnO, instead of placing them on the surface. Investigating two different processes, we found that the best fabrication route is embedding the gold nanoantennas in ZnO using an MBE overgrowth process where a thin ZnO layer was deposited on nanoantennas fabricated on a ZnO substrate. In addition, second harmonic generation measurements show that the embedding leads to an enhancement compared to the emission of nanoantennas placed on the ZnO substrate surface. These promising results facilitate further research to determine the influence of the periodicity of the nanoantenna arrangement of the resulting SHG signal. article_number: '043107' article_type: original author: - first_name: Ruth full_name: Volmert, Ruth last_name: Volmert - first_name: Nils full_name: Weber, Nils last_name: Weber - first_name: Cedrik full_name: Meier, Cedrik id: '20798' last_name: Meier orcid: https://orcid.org/0000-0002-3787-3572 citation: ama: Volmert R, Weber N, Meier C. Nanoantennas embedded in zinc oxide for second harmonic generation enhancement. Journal of Applied Physics. 2020;128(4). doi:10.1063/5.0012813 apa: Volmert, R., Weber, N., & Meier, C. (2020). Nanoantennas embedded in zinc oxide for second harmonic generation enhancement. Journal of Applied Physics, 128(4). https://doi.org/10.1063/5.0012813 bibtex: '@article{Volmert_Weber_Meier_2020, title={Nanoantennas embedded in zinc oxide for second harmonic generation enhancement}, volume={128}, DOI={10.1063/5.0012813}, number={4043107}, journal={Journal of Applied Physics}, author={Volmert, Ruth and Weber, Nils and Meier, Cedrik}, year={2020} }' chicago: Volmert, Ruth, Nils Weber, and Cedrik Meier. “Nanoantennas Embedded in Zinc Oxide for Second Harmonic Generation Enhancement.” Journal of Applied Physics 128, no. 4 (2020). https://doi.org/10.1063/5.0012813. ieee: R. Volmert, N. Weber, and C. Meier, “Nanoantennas embedded in zinc oxide for second harmonic generation enhancement,” Journal of Applied Physics, vol. 128, no. 4, 2020. mla: Volmert, Ruth, et al. “Nanoantennas Embedded in Zinc Oxide for Second Harmonic Generation Enhancement.” Journal of Applied Physics, vol. 128, no. 4, 043107, 2020, doi:10.1063/5.0012813. short: R. Volmert, N. Weber, C. Meier, Journal of Applied Physics 128 (2020). date_created: 2020-12-02T12:57:58Z date_updated: 2022-01-06T06:54:31Z department: - _id: '230' - _id: '429' doi: 10.1063/5.0012813 external_id: isi: - '000557311900001' intvolume: ' 128' isi: '1' issue: '4' language: - iso: eng project: - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '66' name: TRR 142 - Subproject B1 - _id: '56' name: TRR 142 - Project Area C - _id: '75' name: TRR 142 - Subproject C5 publication: Journal of Applied Physics publication_identifier: eissn: - 1089-7550 issn: - 0021-8979 publication_status: published quality_controlled: '1' status: public title: Nanoantennas embedded in zinc oxide for second harmonic generation enhancement type: journal_article user_id: '20798' volume: 128 year: '2020' ... --- _id: '22053' article_number: '023103' author: - first_name: K. J. full_name: Spychala, K. J. last_name: Spychala - first_name: P. full_name: Mackwitz, P. last_name: Mackwitz - first_name: A. full_name: Widhalm, A. last_name: Widhalm - first_name: G. full_name: Berth, G. last_name: Berth - first_name: A. full_name: Zrenner, A. last_name: Zrenner citation: ama: Spychala KJ, Mackwitz P, Widhalm A, Berth G, Zrenner A. Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime. Journal of Applied Physics. 2020. doi:10.1063/1.5133476 apa: Spychala, K. J., Mackwitz, P., Widhalm, A., Berth, G., & Zrenner, A. (2020). Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime. Journal of Applied Physics. https://doi.org/10.1063/1.5133476 bibtex: '@article{Spychala_Mackwitz_Widhalm_Berth_Zrenner_2020, title={Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime}, DOI={10.1063/1.5133476}, number={023103}, journal={Journal of Applied Physics}, author={Spychala, K. J. and Mackwitz, P. and Widhalm, A. and Berth, G. and Zrenner, A.}, year={2020} }' chicago: Spychala, K. J., P. Mackwitz, A. Widhalm, G. Berth, and A. Zrenner. “Spatially Resolved Light Field Analysis of the Second-Harmonic Signal of χ(2)-Materials in the Tight Focusing Regime.” Journal of Applied Physics, 2020. https://doi.org/10.1063/1.5133476. ieee: K. J. Spychala, P. Mackwitz, A. Widhalm, G. Berth, and A. Zrenner, “Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime,” Journal of Applied Physics, 2020. mla: Spychala, K. J., et al. “Spatially Resolved Light Field Analysis of the Second-Harmonic Signal of χ(2)-Materials in the Tight Focusing Regime.” Journal of Applied Physics, 023103, 2020, doi:10.1063/1.5133476. short: K.J. Spychala, P. Mackwitz, A. Widhalm, G. Berth, A. Zrenner, Journal of Applied Physics (2020). date_created: 2021-05-09T06:25:14Z date_updated: 2022-01-06T06:55:23Z department: - _id: '15' - _id: '230' doi: 10.1063/1.5133476 language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime type: journal_article user_id: '606' year: '2020' ... --- _id: '22054' article_number: '023103' author: - first_name: K. J. full_name: Spychala, K. J. last_name: Spychala - first_name: P. full_name: Mackwitz, P. last_name: Mackwitz - first_name: A. full_name: Widhalm, A. last_name: Widhalm - first_name: Gerhard full_name: Berth, Gerhard last_name: Berth - first_name: Artur full_name: Zrenner, Artur id: '606' last_name: Zrenner orcid: 0000-0002-5190-0944 citation: ama: Spychala KJ, Mackwitz P, Widhalm A, Berth G, Zrenner A. Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime. Journal of Applied Physics. 2020. doi:10.1063/1.5133476 apa: Spychala, K. J., Mackwitz, P., Widhalm, A., Berth, G., & Zrenner, A. (2020). Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime. Journal of Applied Physics. https://doi.org/10.1063/1.5133476 bibtex: '@article{Spychala_Mackwitz_Widhalm_Berth_Zrenner_2020, title={Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime}, DOI={10.1063/1.5133476}, number={023103}, journal={Journal of Applied Physics}, author={Spychala, K. J. and Mackwitz, P. and Widhalm, A. and Berth, Gerhard and Zrenner, Artur}, year={2020} }' chicago: Spychala, K. J., P. Mackwitz, A. Widhalm, Gerhard Berth, and Artur Zrenner. “Spatially Resolved Light Field Analysis of the Second-Harmonic Signal of χ(2)-Materials in the Tight Focusing Regime.” Journal of Applied Physics, 2020. https://doi.org/10.1063/1.5133476. ieee: K. J. Spychala, P. Mackwitz, A. Widhalm, G. Berth, and A. Zrenner, “Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime,” Journal of Applied Physics, 2020. mla: Spychala, K. J., et al. “Spatially Resolved Light Field Analysis of the Second-Harmonic Signal of χ(2)-Materials in the Tight Focusing Regime.” Journal of Applied Physics, 023103, 2020, doi:10.1063/1.5133476. short: K.J. Spychala, P. Mackwitz, A. Widhalm, G. Berth, A. Zrenner, Journal of Applied Physics (2020). date_created: 2021-05-09T06:27:56Z date_updated: 2022-01-06T06:55:23Z department: - _id: '15' - _id: '230' doi: 10.1063/1.5133476 language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime type: journal_article user_id: '606' year: '2020' ... --- _id: '22056' article_number: '234102' author: - first_name: K. J. full_name: Spychala, K. J. last_name: Spychala - first_name: P. full_name: Mackwitz, P. last_name: Mackwitz - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: A. full_name: Widhalm, A. last_name: Widhalm - first_name: Gerhard full_name: Berth, Gerhard id: '53' last_name: Berth - first_name: Christine full_name: Silberhorn, Christine id: '26263' last_name: Silberhorn - first_name: Artur full_name: Zrenner, Artur id: '606' last_name: Zrenner orcid: 0000-0002-5190-0944 citation: ama: 'Spychala KJ, Mackwitz P, Rüsing M, et al. Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism. Journal of Applied Physics. Published online 2020. doi:10.1063/5.0025284' apa: 'Spychala, K. J., Mackwitz, P., Rüsing, M., Widhalm, A., Berth, G., Silberhorn, C., & Zrenner, A. (2020). Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism. Journal of Applied Physics, Article 234102. https://doi.org/10.1063/5.0025284' bibtex: '@article{Spychala_Mackwitz_Rüsing_Widhalm_Berth_Silberhorn_Zrenner_2020, title={Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism}, DOI={10.1063/5.0025284}, number={234102}, journal={Journal of Applied Physics}, author={Spychala, K. J. and Mackwitz, P. and Rüsing, Michael and Widhalm, A. and Berth, Gerhard and Silberhorn, Christine and Zrenner, Artur}, year={2020} }' chicago: 'Spychala, K. J., P. Mackwitz, Michael Rüsing, A. Widhalm, Gerhard Berth, Christine Silberhorn, and Artur Zrenner. “Nonlinear Focal Mapping of Ferroelectric Domain Walls in LiNbO3: Analysis of the SHG Microscopy Contrast Mechanism.” Journal of Applied Physics, 2020. https://doi.org/10.1063/5.0025284.' ieee: 'K. J. Spychala et al., “Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism,” Journal of Applied Physics, Art. no. 234102, 2020, doi: 10.1063/5.0025284.' mla: 'Spychala, K. J., et al. “Nonlinear Focal Mapping of Ferroelectric Domain Walls in LiNbO3: Analysis of the SHG Microscopy Contrast Mechanism.” Journal of Applied Physics, 234102, 2020, doi:10.1063/5.0025284.' short: K.J. Spychala, P. Mackwitz, M. Rüsing, A. Widhalm, G. Berth, C. Silberhorn, A. Zrenner, Journal of Applied Physics (2020). date_created: 2021-05-09T06:33:08Z date_updated: 2023-10-09T08:07:57Z department: - _id: '15' - _id: '230' doi: 10.1063/5.0025284 language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: 'Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism' type: journal_article user_id: '14931' year: '2020' ...