--- _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: '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: '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: '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: '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' ... --- _id: '47955' abstract: - lang: eng text: Quasi-phase-matched grating structures in lithium niobate waveguides with sub-micrometer periodicities will benefit the development of short-wavelength nonlinear optical devices. Here, we report on the reproducible formation of periodically poled domains in x-cut single-crystalline thin-film lithium niobate with periodicities as short as 600 nm. Shaped single-voltage poling pulses were applied to electrode structures that were fabricated by a combination of electron-beam and direct-writing laser lithography. Evidence of successful poling with good quality was obtained through second-harmonic microscopy and piezoresponse force microscopy imaging. For the sub-micrometer period structures, we observed patterns with a double periodicity formed by domain interactions and features with sizes <200 nm. article_number: '193104' article_type: original author: - first_name: Jie full_name: Zhao, Jie last_name: Zhao - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: Matthias full_name: Roeper, Matthias last_name: Roeper - first_name: Lukas M. full_name: Eng, Lukas M. last_name: Eng - first_name: Shayan full_name: Mookherjea, Shayan last_name: Mookherjea citation: ama: Zhao J, Rüsing M, Roeper M, Eng LM, Mookherjea S. Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity. Journal of Applied Physics. 2020;127(19). doi:10.1063/1.5143266 apa: Zhao, J., Rüsing, M., Roeper, M., Eng, L. M., & Mookherjea, S. (2020). Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity. Journal of Applied Physics, 127(19), Article 193104. https://doi.org/10.1063/1.5143266 bibtex: '@article{Zhao_Rüsing_Roeper_Eng_Mookherjea_2020, title={Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity}, volume={127}, DOI={10.1063/1.5143266}, number={19193104}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Zhao, Jie and Rüsing, Michael and Roeper, Matthias and Eng, Lukas M. and Mookherjea, Shayan}, year={2020} }' chicago: Zhao, Jie, Michael Rüsing, Matthias Roeper, Lukas M. Eng, and Shayan Mookherjea. “Poling Thin-Film x-Cut Lithium Niobate for Quasi-Phase Matching with Sub-Micrometer Periodicity.” Journal of Applied Physics 127, no. 19 (2020). https://doi.org/10.1063/1.5143266. ieee: 'J. Zhao, M. Rüsing, M. Roeper, L. M. Eng, and S. Mookherjea, “Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity,” Journal of Applied Physics, vol. 127, no. 19, Art. no. 193104, 2020, doi: 10.1063/1.5143266.' mla: Zhao, Jie, et al. “Poling Thin-Film x-Cut Lithium Niobate for Quasi-Phase Matching with Sub-Micrometer Periodicity.” Journal of Applied Physics, vol. 127, no. 19, 193104, AIP Publishing, 2020, doi:10.1063/1.5143266. short: J. Zhao, M. Rüsing, M. Roeper, L.M. Eng, S. Mookherjea, Journal of Applied Physics 127 (2020). date_created: 2023-10-11T08:06:39Z date_updated: 2023-10-11T08:07:28Z doi: 10.1063/1.5143266 intvolume: ' 127' issue: '19' 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: Poling thin-film x-cut lithium niobate for quasi-phase matching with sub-micrometer periodicity type: journal_article user_id: '22501' volume: 127 year: '2020' ... --- _id: '8646' article_number: '095703' author: - first_name: M. full_name: Deppe, M. last_name: Deppe - first_name: J. W. full_name: Gerlach, J. W. last_name: Gerlach - first_name: S. full_name: Shvarkov, S. last_name: Shvarkov - first_name: D. full_name: Rogalla, D. last_name: Rogalla - first_name: H.-W. full_name: Becker, H.-W. last_name: Becker - first_name: Dirk full_name: Reuter, Dirk id: '37763' last_name: Reuter - first_name: Donat Josef full_name: As, Donat Josef id: '14' last_name: As orcid: 0000-0003-1121-3565 citation: ama: Deppe M, Gerlach JW, Shvarkov S, et al. Germanium doping of cubic GaN grown by molecular beam epitaxy. Journal of Applied Physics. 2019. doi:10.1063/1.5066095 apa: Deppe, M., Gerlach, J. W., Shvarkov, S., Rogalla, D., Becker, H.-W., Reuter, D., & As, D. J. (2019). Germanium doping of cubic GaN grown by molecular beam epitaxy. Journal of Applied Physics. https://doi.org/10.1063/1.5066095 bibtex: '@article{Deppe_Gerlach_Shvarkov_Rogalla_Becker_Reuter_As_2019, title={Germanium doping of cubic GaN grown by molecular beam epitaxy}, DOI={10.1063/1.5066095}, number={095703}, journal={Journal of Applied Physics}, author={Deppe, M. and Gerlach, J. W. and Shvarkov, S. and Rogalla, D. and Becker, H.-W. and Reuter, Dirk and As, Donat Josef}, year={2019} }' chicago: Deppe, M., J. W. Gerlach, S. Shvarkov, D. Rogalla, H.-W. Becker, Dirk Reuter, and Donat Josef As. “Germanium Doping of Cubic GaN Grown by Molecular Beam Epitaxy.” Journal of Applied Physics, 2019. https://doi.org/10.1063/1.5066095. ieee: M. Deppe et al., “Germanium doping of cubic GaN grown by molecular beam epitaxy,” Journal of Applied Physics, 2019. mla: Deppe, M., et al. “Germanium Doping of Cubic GaN Grown by Molecular Beam Epitaxy.” Journal of Applied Physics, 095703, 2019, doi:10.1063/1.5066095. short: M. Deppe, J.W. Gerlach, S. Shvarkov, D. Rogalla, H.-W. Becker, D. Reuter, D.J. As, Journal of Applied Physics (2019). date_created: 2019-03-26T12:48:57Z date_updated: 2022-01-06T07:03:58Z department: - _id: '230' - _id: '429' doi: 10.1063/1.5066095 language: - iso: eng project: - _id: '67' name: TRR 142 - Subproject B2 publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Germanium doping of cubic GaN grown by molecular beam epitaxy type: journal_article user_id: '14' year: '2019' ... --- _id: '9698' article_number: '073103' author: - first_name: C. full_name: Golla, C. last_name: Golla - first_name: N. full_name: Weber, N. 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: Golla C, Weber N, Meier C. Zinc oxide based dielectric nanoantennas for efficient nonlinear frequency conversion. Journal of Applied Physics. 2019;125(7). doi:10.1063/1.5082720 apa: Golla, C., Weber, N., & Meier, C. (2019). Zinc oxide based dielectric nanoantennas for efficient nonlinear frequency conversion. Journal of Applied Physics, 125(7). https://doi.org/10.1063/1.5082720 bibtex: '@article{Golla_Weber_Meier_2019, title={Zinc oxide based dielectric nanoantennas for efficient nonlinear frequency conversion}, volume={125}, DOI={10.1063/1.5082720}, number={7073103}, journal={Journal of Applied Physics}, author={Golla, C. and Weber, N. and Meier, Cedrik}, year={2019} }' chicago: Golla, C., N. Weber, and Cedrik Meier. “Zinc Oxide Based Dielectric Nanoantennas for Efficient Nonlinear Frequency Conversion.” Journal of Applied Physics 125, no. 7 (2019). https://doi.org/10.1063/1.5082720. ieee: C. Golla, N. Weber, and C. Meier, “Zinc oxide based dielectric nanoantennas for efficient nonlinear frequency conversion,” Journal of Applied Physics, vol. 125, no. 7, 2019. mla: Golla, C., et al. “Zinc Oxide Based Dielectric Nanoantennas for Efficient Nonlinear Frequency Conversion.” Journal of Applied Physics, vol. 125, no. 7, 073103, 2019, doi:10.1063/1.5082720. short: C. Golla, N. Weber, C. Meier, Journal of Applied Physics 125 (2019). date_created: 2019-05-08T07:06:11Z date_updated: 2022-01-06T07:04:18Z department: - _id: '15' - _id: '35' - _id: '287' - _id: '230' doi: 10.1063/1.5082720 intvolume: ' 125' issue: '7' 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: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Zinc oxide based dielectric nanoantennas for efficient nonlinear frequency conversion type: journal_article user_id: '20798' volume: 125 year: '2019' ... --- _id: '9897' article_number: '193104' author: - first_name: Maximilian full_name: Protte, Maximilian last_name: Protte - first_name: Nils full_name: Weber, Nils last_name: Weber - first_name: Christian full_name: Golla, Christian last_name: Golla - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 - first_name: Cedrik full_name: Meier, Cedrik id: '20798' last_name: Meier orcid: https://orcid.org/0000-0002-3787-3572 citation: ama: Protte M, Weber N, Golla C, Zentgraf T, Meier C. Strong nonlinear optical response from ZnO by coupled and lattice-matched nanoantennas. Journal of Applied Physics. 2019;125. doi:10.1063/1.5093257 apa: Protte, M., Weber, N., Golla, C., Zentgraf, T., & Meier, C. (2019). Strong nonlinear optical response from ZnO by coupled and lattice-matched nanoantennas. Journal of Applied Physics, 125. https://doi.org/10.1063/1.5093257 bibtex: '@article{Protte_Weber_Golla_Zentgraf_Meier_2019, title={Strong nonlinear optical response from ZnO by coupled and lattice-matched nanoantennas}, volume={125}, DOI={10.1063/1.5093257}, number={193104}, journal={Journal of Applied Physics}, author={Protte, Maximilian and Weber, Nils and Golla, Christian and Zentgraf, Thomas and Meier, Cedrik}, year={2019} }' chicago: Protte, Maximilian, Nils Weber, Christian Golla, Thomas Zentgraf, and Cedrik Meier. “Strong Nonlinear Optical Response from ZnO by Coupled and Lattice-Matched Nanoantennas.” Journal of Applied Physics 125 (2019). https://doi.org/10.1063/1.5093257. ieee: M. Protte, N. Weber, C. Golla, T. Zentgraf, and C. Meier, “Strong nonlinear optical response from ZnO by coupled and lattice-matched nanoantennas,” Journal of Applied Physics, vol. 125, 2019. mla: Protte, Maximilian, et al. “Strong Nonlinear Optical Response from ZnO by Coupled and Lattice-Matched Nanoantennas.” Journal of Applied Physics, vol. 125, 193104, 2019, doi:10.1063/1.5093257. short: M. Protte, N. Weber, C. Golla, T. Zentgraf, C. Meier, Journal of Applied Physics 125 (2019). date_created: 2019-05-21T08:35:49Z date_updated: 2020-08-21T13:52:51Z department: - _id: '15' - _id: '287' - _id: '35' - _id: '230' - _id: '289' doi: 10.1063/1.5093257 intvolume: ' 125' 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: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Strong nonlinear optical response from ZnO by coupled and lattice-matched nanoantennas type: journal_article user_id: '30525' volume: 125 year: '2019' ... --- _id: '13965' article_number: '153901' author: - first_name: J. H. full_name: Buß, J. H. last_name: Buß - first_name: T. full_name: Schupp, T. last_name: Schupp - first_name: Donat Josef full_name: As, Donat Josef id: '14' last_name: As orcid: 0000-0003-1121-3565 - first_name: D. full_name: Hägele, D. last_name: Hägele - first_name: J. full_name: Rudolph, J. last_name: Rudolph citation: ama: Buß JH, Schupp T, As DJ, Hägele D, Rudolph J. Optical excitation density dependence of spin dynamics in bulk cubic GaN. Journal of Applied Physics. 2019. doi:10.1063/1.5123914 apa: Buß, J. H., Schupp, T., As, D. J., Hägele, D., & Rudolph, J. (2019). Optical excitation density dependence of spin dynamics in bulk cubic GaN. Journal of Applied Physics. https://doi.org/10.1063/1.5123914 bibtex: '@article{Buß_Schupp_As_Hägele_Rudolph_2019, title={Optical excitation density dependence of spin dynamics in bulk cubic GaN}, DOI={10.1063/1.5123914}, number={153901}, journal={Journal of Applied Physics}, author={Buß, J. H. and Schupp, T. and As, Donat Josef and Hägele, D. and Rudolph, J.}, year={2019} }' chicago: Buß, J. H., T. Schupp, Donat Josef As, D. Hägele, and J. Rudolph. “Optical Excitation Density Dependence of Spin Dynamics in Bulk Cubic GaN.” Journal of Applied Physics, 2019. https://doi.org/10.1063/1.5123914. ieee: J. H. Buß, T. Schupp, D. J. As, D. Hägele, and J. Rudolph, “Optical excitation density dependence of spin dynamics in bulk cubic GaN,” Journal of Applied Physics, 2019. mla: Buß, J. H., et al. “Optical Excitation Density Dependence of Spin Dynamics in Bulk Cubic GaN.” Journal of Applied Physics, 153901, 2019, doi:10.1063/1.5123914. short: J.H. Buß, T. Schupp, D.J. As, D. Hägele, J. Rudolph, Journal of Applied Physics (2019). date_created: 2019-10-22T12:26:02Z date_updated: 2022-01-06T06:51:48Z department: - _id: '230' - _id: '429' doi: 10.1063/1.5123914 language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: Optical excitation density dependence of spin dynamics in bulk cubic GaN type: journal_article user_id: '14' year: '2019' ... --- _id: '47951' abstract: - lang: eng text: Thin film lithium niobate has been of great interest recently, and an understanding of periodically poled thin films is crucial for both fundamental physics and device developments. Second-harmonic (SH) microscopy allows for the noninvasive visualization and analysis of ferroelectric domain structures and walls. While the technique is well understood in bulk lithium niobate, SH microscopy in thin films is largely influenced by interfacial reflections and resonant enhancements, which depend on film thicknesses and substrate materials. We present a comprehensive analysis of SH microscopy in x-cut lithium niobate thin films, based on a full three-dimensional focus calculation and accounting for interface reflections. We show that the dominant signal in backreflection originates from a copropagating phase-matched process observed through reflections, rather than direct detection of the counterpropagating signal as in bulk samples. We simulate the SH signatures of domain structures by a simple model of the domain wall as an extensionless transition from a −χ(2) to a +χ(2) region. This allows us to explain the main observation of domain structures in the thin-film geometry, and, in particular, we show that the SH signal from thin poled films allows to unambiguously distinguish areas, which are completely or only partly inverted in depth. article_number: '114105' author: - first_name: Michael full_name: Rüsing, Michael id: '22501' last_name: Rüsing orcid: 0000-0003-4682-4577 - first_name: J. full_name: Zhao, J. last_name: Zhao - first_name: S. full_name: Mookherjea, S. last_name: Mookherjea citation: ama: 'Rüsing M, Zhao J, Mookherjea S. Second harmonic microscopy of poled x-cut thin film lithium niobate: Understanding the contrast mechanism. Journal of Applied Physics. 2019;126(11). doi:10.1063/1.5113727' apa: 'Rüsing, M., Zhao, J., & Mookherjea, S. (2019). Second harmonic microscopy of poled x-cut thin film lithium niobate: Understanding the contrast mechanism. Journal of Applied Physics, 126(11), Article 114105. https://doi.org/10.1063/1.5113727' bibtex: '@article{Rüsing_Zhao_Mookherjea_2019, title={Second harmonic microscopy of poled x-cut thin film lithium niobate: Understanding the contrast mechanism}, volume={126}, DOI={10.1063/1.5113727}, number={11114105}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Rüsing, Michael and Zhao, J. and Mookherjea, S.}, year={2019} }' chicago: 'Rüsing, Michael, J. Zhao, and S. Mookherjea. “Second Harmonic Microscopy of Poled X-Cut Thin Film Lithium Niobate: Understanding the Contrast Mechanism.” Journal of Applied Physics 126, no. 11 (2019). https://doi.org/10.1063/1.5113727.' ieee: 'M. Rüsing, J. Zhao, and S. Mookherjea, “Second harmonic microscopy of poled x-cut thin film lithium niobate: Understanding the contrast mechanism,” Journal of Applied Physics, vol. 126, no. 11, Art. no. 114105, 2019, doi: 10.1063/1.5113727.' mla: 'Rüsing, Michael, et al. “Second Harmonic Microscopy of Poled X-Cut Thin Film Lithium Niobate: Understanding the Contrast Mechanism.” Journal of Applied Physics, vol. 126, no. 11, 114105, AIP Publishing, 2019, doi:10.1063/1.5113727.' short: M. Rüsing, J. Zhao, S. Mookherjea, Journal of Applied Physics 126 (2019). date_created: 2023-10-11T07:47:03Z date_updated: 2023-10-11T07:48:11Z doi: 10.1063/1.5113727 extern: '1' intvolume: ' 126' issue: '11' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/1.5113727/15233243/114105_1_online.pdf oa: '1' publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: 'Second harmonic microscopy of poled x-cut thin film lithium niobate: Understanding the contrast mechanism' type: journal_article user_id: '22501' volume: 126 year: '2019' ... --- _id: '1327' article_number: '103101' author: - first_name: N. full_name: Weber, N. last_name: Weber - first_name: S. P. full_name: Hoffmann, S. P. last_name: Hoffmann - first_name: M. full_name: Albert, M. last_name: Albert - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 - first_name: Cedrik full_name: Meier, Cedrik id: '20798' last_name: Meier orcid: https://orcid.org/0000-0002-3787-3572 citation: ama: Weber N, Hoffmann SP, Albert M, Zentgraf T, Meier C. Efficient frequency conversion by combined photonic–plasmonic mode coupling. Journal of Applied Physics. 2018;123(10). doi:10.1063/1.5017010 apa: Weber, N., Hoffmann, S. P., Albert, M., Zentgraf, T., & Meier, C. (2018). Efficient frequency conversion by combined photonic–plasmonic mode coupling. Journal of Applied Physics, 123(10). https://doi.org/10.1063/1.5017010 bibtex: '@article{Weber_Hoffmann_Albert_Zentgraf_Meier_2018, title={Efficient frequency conversion by combined photonic–plasmonic mode coupling}, volume={123}, DOI={10.1063/1.5017010}, number={10103101}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Weber, N. and Hoffmann, S. P. and Albert, M. and Zentgraf, Thomas and Meier, Cedrik}, year={2018} }' chicago: Weber, N., S. P. Hoffmann, M. Albert, Thomas Zentgraf, and Cedrik Meier. “Efficient Frequency Conversion by Combined Photonic–Plasmonic Mode Coupling.” Journal of Applied Physics 123, no. 10 (2018). https://doi.org/10.1063/1.5017010. ieee: N. Weber, S. P. Hoffmann, M. Albert, T. Zentgraf, and C. Meier, “Efficient frequency conversion by combined photonic–plasmonic mode coupling,” Journal of Applied Physics, vol. 123, no. 10, 2018. mla: Weber, N., et al. “Efficient Frequency Conversion by Combined Photonic–Plasmonic Mode Coupling.” Journal of Applied Physics, vol. 123, no. 10, 103101, AIP Publishing, 2018, doi:10.1063/1.5017010. short: N. Weber, S.P. Hoffmann, M. Albert, T. Zentgraf, C. Meier, Journal of Applied Physics 123 (2018). date_created: 2018-03-16T08:41:10Z date_updated: 2022-01-06T06:51:31Z department: - _id: '15' - _id: '230' - _id: '287' - _id: '35' - _id: '289' doi: 10.1063/1.5017010 intvolume: ' 123' issue: '10' language: - iso: eng project: - _id: '53' name: TRR 142 - _id: '56' name: TRR 142 - Project Area C - _id: '75' name: TRR 142 - Subproject C5 - _id: '54' name: TRR 142 - Project Area A - _id: '62' name: TRR 142 - Subproject A5 publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published publisher: AIP Publishing status: public title: Efficient frequency conversion by combined photonic–plasmonic mode coupling type: journal_article user_id: '82901' volume: 123 year: '2018' ... --- _id: '22569' article_number: '171912' author: - first_name: Vincent full_name: Layes, Vincent last_name: Layes - first_name: Sascha full_name: Monje, Sascha last_name: Monje - first_name: Carles full_name: Corbella, Carles last_name: Corbella - first_name: Volker full_name: Schulz-von der Gathen, Volker last_name: Schulz-von der Gathen - first_name: Achim full_name: von Keudell, Achim last_name: von Keudell - first_name: Maria Teresa full_name: de los Arcos de Pedro, Maria Teresa id: '54556' last_name: de los Arcos de Pedro citation: ama: 'Layes V, Monje S, Corbella C, Schulz-von der Gathen V, von Keudell A, de los Arcos de Pedro MT. Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics. Journal of Applied Physics. Published online 2017. doi:10.1063/1.4977820' apa: 'Layes, V., Monje, S., Corbella, C., Schulz-von der Gathen, V., von Keudell, A., & de los Arcos de Pedro, M. T. (2017). Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics. Journal of Applied Physics, Article 171912. https://doi.org/10.1063/1.4977820' bibtex: '@article{Layes_Monje_Corbella_Schulz-von der Gathen_von Keudell_de los Arcos de Pedro_2017, title={Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics}, DOI={10.1063/1.4977820}, number={171912}, journal={Journal of Applied Physics}, author={Layes, Vincent and Monje, Sascha and Corbella, Carles and Schulz-von der Gathen, Volker and von Keudell, Achim and de los Arcos de Pedro, Maria Teresa}, year={2017} }' chicago: 'Layes, Vincent, Sascha Monje, Carles Corbella, Volker Schulz-von der Gathen, Achim von Keudell, and Maria Teresa de los Arcos de Pedro. “Composite Targets in HiPIMS Plasmas: Correlation of in-Vacuum XPS Characterization and Optical Plasma Diagnostics.” Journal of Applied Physics, 2017. https://doi.org/10.1063/1.4977820.' ieee: 'V. Layes, S. Monje, C. Corbella, V. Schulz-von der Gathen, A. von Keudell, and M. T. de los Arcos de Pedro, “Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics,” Journal of Applied Physics, Art. no. 171912, 2017, doi: 10.1063/1.4977820.' mla: 'Layes, Vincent, et al. “Composite Targets in HiPIMS Plasmas: Correlation of in-Vacuum XPS Characterization and Optical Plasma Diagnostics.” Journal of Applied Physics, 171912, 2017, doi:10.1063/1.4977820.' short: V. Layes, S. Monje, C. Corbella, V. Schulz-von der Gathen, A. von Keudell, M.T. de los Arcos de Pedro, Journal of Applied Physics (2017). date_created: 2021-07-07T09:08:54Z date_updated: 2023-01-24T08:14:07Z department: - _id: '302' doi: 10.1063/1.4977820 language: - iso: eng publication: Journal of Applied Physics publication_identifier: issn: - 0021-8979 - 1089-7550 publication_status: published status: public title: 'Composite targets in HiPIMS plasmas: Correlation of in-vacuum XPS characterization and optical plasma diagnostics' type: journal_article user_id: '54556' year: '2017' ...