@article{47997,
  abstract     = {{The crystal family of potassium titanyl phosphate (KTiOPO4) is a promising material group for applications in quantum and nonlinear optics. The fabrication of low-loss optical waveguides, as well as high-grade periodically poled ferroelectric domain structures, requires a profound understanding of the material properties and crystal structure. In this regard, Raman spectroscopy offers the possibility to study and visualize domain structures, strain, defects, and the local stoichiometry, which are all factors impacting device performance. However, the accurate interpretation of Raman spectra and their changes with respect to extrinsic and intrinsic defects requires a thorough assignment of the Raman modes to their respective crystal features, which to date is only partly conducted based on phenomenological modelling. To address this issue, we calculated the phonon spectra of potassium titanyl phosphate and the related compounds rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenate (KTiOAsO4) based on density functional theory and compared them with experimental data. Overall, this allows us to assign various spectral features to eigenmodes of lattice substructures with improved detail compared to previous assignments. Nevertheless, the analysis also shows that not all features of the spectra can unambigiously be explained yet. A possible explanation might be that defects or long range fields not included in the modeling play a crucial rule for the resulting Raman spectrum. In conclusion, this work provides an improved foundation into the vibrational properties in the KTiOPO4 material family.}},
  author       = {{Neufeld, Sergej and Gerstmann, Uwe and Padberg, Laura and Eigner, Christof and Berth, Gerhard and Silberhorn, Christine and Eng, Lukas M. and Schmidt, Wolf Gero and Rüsing, Michael}},
  issn         = {{2073-4352}},
  journal      = {{Crystals}},
  keywords     = {{Inorganic Chemistry, Condensed Matter Physics, General Materials Science, General Chemical Engineering}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Vibrational Properties of the Potassium Titanyl Phosphate Crystal Family}}},
  doi          = {{10.3390/cryst13101423}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{54852,
  abstract     = {{<jats:p>The crystal family of potassium titanyl phosphate (KTiOPO4) is a promising material group for applications in quantum and nonlinear optics. The fabrication of low-loss optical waveguides, as well as high-grade periodically poled ferroelectric domain structures, requires a profound understanding of the material properties and crystal structure. In this regard, Raman spectroscopy offers the possibility to study and visualize domain structures, strain, defects, and the local stoichiometry, which are all factors impacting device performance. However, the accurate interpretation of Raman spectra and their changes with respect to extrinsic and intrinsic defects requires a thorough assignment of the Raman modes to their respective crystal features, which to date is only partly conducted based on phenomenological modelling. To address this issue, we calculated the phonon spectra of potassium titanyl phosphate and the related compounds rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenate (KTiOAsO4) based on density functional theory and compared them with experimental data. Overall, this allows us to assign various spectral features to eigenmodes of lattice substructures with improved detail compared to previous assignments. Nevertheless, the analysis also shows that not all features of the spectra can unambigiously be explained yet. A possible explanation might be that defects or long range fields not included in the modeling play a crucial rule for the resulting Raman spectrum. In conclusion, this work provides an improved foundation into the vibrational properties in the KTiOPO4 material family.</jats:p>}},
  author       = {{Neufeld, Sergej and Gerstmann, Uwe and Padberg, Laura and Eigner, Christof and Berth, Gerhard and Silberhorn, Christine and Eng, Lukas M. and Schmidt, Wolf Gero and Rüsing, Michael}},
  issn         = {{2073-4352}},
  journal      = {{Crystals}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Vibrational Properties of the Potassium Titanyl Phosphate Crystal Family}}},
  doi          = {{10.3390/cryst13101423}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{23826,
  abstract     = {{<jats:p>Potassium titanyl phosphate (KTP) is a nonlinear optical material with applications in high-power frequency conversion or quasi-phase matching in submicron period domain grids. A prerequisite for these applications is a precise control and understanding of the poling mechanisms to enable the fabrication of high-grade domain grids. In contrast to the widely used material lithium niobate, the domain growth in KTP is less studied, because many standard methods, such as selective etching or polarization microscopy, provides less insight or are not applicable on non-polar surfaces, respectively. In this work, we present results of confocal Raman-spectroscopy of the ferroelectric domain structure in KTP. This analytical method allows for the visualization of domain grids of the non-polar KTP y-face and therefore more insight into the domain-growth and -structure in KTP, which can be used for improved domain fabrication.</jats:p>}},
  author       = {{Brockmeier, Julian and Mackwitz, Peter Walter Martin and Rüsing, Michael and Eigner, Christof and Padberg, Laura and Santandrea, Matteo and Silberhorn, Christine and Zrenner, Artur and Berth, Gerhard}},
  issn         = {{2073-4352}},
  journal      = {{Crystals}},
  title        = {{{Non-Invasive Visualization of Ferroelectric Domain Structures on the Non-Polar y-Surface of KTiOPO4 via Raman Imaging}}},
  doi          = {{10.3390/cryst11091086}},
  year         = {{2021}},
}

@article{22056,
  author       = {{Spychala, K. J. and Mackwitz, P. and Rüsing, Michael and Widhalm, A. and Berth, Gerhard and Silberhorn, Christine and Zrenner, Artur}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  title        = {{{Nonlinear focal mapping of ferroelectric domain walls in LiNbO3: Analysis of the SHG microscopy contrast mechanism}}},
  doi          = {{10.1063/5.0025284}},
  year         = {{2020}},
}

@article{25920,
  author       = {{Padberg, Laura and Santandrea, Matteo and Rüsing, Michael and Brockmeier, Julian and Mackwitz, Peter and Berth, Gerhard and Zrenner, Artur and Eigner, Christof and Silberhorn, Christine}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  title        = {{{Characterisation of width-dependent diffusion dynamics in rubidium-exchanged KTP waveguides}}},
  doi          = {{10.1364/oe.397074}},
  year         = {{2020}},
}

@article{4769,
  abstract     = {{In recent years, Raman spectroscopy has been used to visualize and analyze ferroelectric domain structures.
The technique makes use of the fact that the intensity or frequency of certain phonons is strongly influenced
by the presence of domain walls. Although the method is used frequently, the underlying mechanism responsible
for the changes in the spectra is not fully understood. This inhibits deeper analysis of domain structures based
on this method. Two different models have been proposed. However, neither model completely explains all
observations. In this work, we have systematically investigated domain walls in different scattering geometries
with Raman spectroscopy in the common ferroelectric materials used in integrated optics, i.e., KTiOPO4,
LiNbO3, and LiTaO3. Based on the two models, we can demonstrate that the observed contrast for domain
walls is in fact based on two different effects. We can identify on the one hand microscopic changes at the
domain wall, e.g., strain and electric fields, and on the other hand a macroscopic change of selection rules at the
domain wall. While the macroscopic relaxation of selection rules can be explained by the directional dispersion
of the phonons in agreement with previous propositions, the microscopic changes can be explained qualitatively
in terms of a simplified atomistic model.}},
  author       = {{Rüsing, Michael and Neufeld, Sergej and Brockmeier, Julian and Eigner, Christof and Mackwitz, P. and Spychala, K. and Silberhorn, Christine and Schmidt, Wolf Gero and Berth, Gerhard and Zrenner, Artur and Sanna, S.}},
  issn         = {{2475-9953}},
  journal      = {{Physical Review Materials}},
  number       = {{10}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Imaging of 180∘ ferroelectric domain walls in uniaxial ferroelectrics by confocal Raman spectroscopy: Unraveling the contrast mechanism}}},
  doi          = {{10.1103/physrevmaterials.2.103801}},
  volume       = {{2}},
  year         = {{2018}},
}

@article{3434,
  abstract     = {{In this work we study the impact of ion implantation on the nonlinear optical properties in MgO:LiNbO3 via confocal second-harmonic microscopy. In detail, we spatially characterize the nonlinear susceptibility in carbon-ion implanted lithium niobate planar waveguides for different implantation energies and fluences, as well as the effect of annealing. In a further step, a computational simulation is used to calculate the implantation range of carbon-ions and the corresponding defect density distribution. A comparison between the simulation and the experimental data indicates that the depth profile of the second-order effective nonlinear coefficient is directly connected to the defect density that is induced by the ion irradiation. Furthermore it can be demonstrated that the annealing treatment partially recovers the second-order optical susceptibility.}},
  author       = {{Spychala, Kai J. and Berth, Gerhard and Widhalm, Alex and Rüsing, Michael and Wang, Lei and Sanna, Simone and Zrenner, Artur}},
  issn         = {{1094-4087}},
  journal      = {{OPTICS EXPRESS}},
  number       = {{18}},
  pages        = {{21444----21453}},
  title        = {{{Impact of carbon-ion implantation on the nonlinear optical susceptibility of LiNbO3}}},
  doi          = {{10.1364/OE.25.021444}},
  year         = {{2017}},
}

@inproceedings{3798,
  author       = {{Hett, Thomas and Frers, Torsten and Widhalm, Alex and Berth, Gerhard and Hilleringmann, Ulrich and Zrenner, Artur}},
  booktitle    = {{Smart Systems Integration 2016 - International Conference and Exhibition on Integration Issues of Miniaturized Systems, SSI 2016}},
  location     = {{Munich}},
  pages        = {{400 -- 403}},
  title        = {{{Silicon oxynitride microdisk resonators for integrated waveguide coupling}}},
  year         = {{2016}},
}

@article{4239,
  abstract     = {{Confocal Raman spectroscopy is applied to identify ferroelectric domain structure sensitive
phonon modes in potassium titanyl phosphate. Therefore, polarization-dependent measurements in
various scattering configurations have been performed to characterize the fundamental Raman
spectra of the material. The obtained spectra are discussed qualitatively based on an internal mode
assignment. In the main part of this work, we have characterized z-cut periodically poled potassium
titanyl phosphate in terms of polarity- and structure-sensitive phonon modes. Here, we find vibrations
whose intensities are linked to the ferroelectric domain walls. We interpret this in terms of
changes in the polarizability originating from strain induced by domain boundaries and the inner
field distribution. Hence, a direct and 3D visualization of ferroelectric domain structures becomes
possible in potassium titanyl phosphate.}},
  author       = {{Rüsing, Michael and Eigner, Christof and Mackwitz, P. and Berth, Gerhard and Silberhorn, Christine and Zrenner, Artur}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  number       = {{4}},
  publisher    = {{AIP Publishing}},
  title        = {{{Identification of ferroelectric domain structure sensitive phonon modes in potassium titanyl phosphate: A fundamental study}}},
  doi          = {{10.1063/1.4940964}},
  volume       = {{119}},
  year         = {{2016}},
}

@article{4237,
  abstract     = {{We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film.
Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding
properties offering high mode confinement and smaller devices compared to in-diffused waveguides
in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not
require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest
nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain
inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a
stack of LN thin film/SiO2 layer/Bulk LN, which were patterned by optical lithography. The periodic
domain inversion was verified by non-invasive confocal second harmonic microscopy. Our
results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures
can be interpreted in terms of spatially, overlapping domain filaments which start their
growth on the þz side.}},
  author       = {{Mackwitz, P. and Rüsing, Michael and Berth, Gerhard and Widhalm, A. and Müller, K. and Zrenner, Artur}},
  issn         = {{0003-6951}},
  journal      = {{Applied Physics Letters}},
  number       = {{15}},
  publisher    = {{AIP Publishing}},
  title        = {{{Periodic domain inversion in x-cut single-crystal lithium niobate thin film}}},
  doi          = {{10.1063/1.4946010}},
  volume       = {{108}},
  year         = {{2016}},
}

@article{4240,
  abstract     = {{Cubic gallium nitride (GaN) films are analyzed with highresolution X-ray diffraction (HRXRD) and Raman spectroscopy. Several cubic GaN layers were grown on 3C-SiC (001) substrate by radio-frequency plasma-assisted molecular beam epitaxy. The layer thickness of the cubic GaN was varied between 75 and 505 nm. The HRXRD analysis reveals a reduction of the full-width at half-maximum (FWHM) of omega scans for growing layer thicknesses, which is caused by a partial compensation of defects. The Raman characterization confirms well-formed c-GaN layers. A more detailed examination of the longitudinal optical mode hints at a correlation of the FWHM of the Raman mode with the dislocation density, which shows the possibility to determine dislocation densities by Ramanspectroscopy on a micrometer scale, which is not possible by HRXRD. Furthermore, this Raman analysis shows that normalized Raman spectra present an alternative way to determine layer thicknesses of thin GaN films.}},
  author       = {{Rüsing, Michael and Wecker, T. and Berth, Gerhard and As, Donat Josef and Zrenner, Artur}},
  issn         = {{0370-1972}},
  journal      = {{physica status solidi (b)}},
  keywords     = {{cubic gallium nitride, dislocation density, HRXRD, Raman spectroscopy}},
  number       = {{4}},
  pages        = {{778--782}},
  publisher    = {{Wiley}},
  title        = {{{Joint Raman spectroscopy and HRXRD investigation of cubic gallium nitride layers grown on 3C-SiC}}},
  doi          = {{10.1002/pssb.201552592}},
  volume       = {{253}},
  year         = {{2016}},
}

@article{10026,
  abstract     = {{Congruent lithium niobate and lithium tantalate mixed crystals have been grown over the complete
compositional range with the Czochralski method. The structural and vibrational properties of the mixed
crystals are studied extensively by x-ray diffraction measurements, Raman spectroscopy, and density functional
theory. The measured lattice parameters and vibrational frequencies are in good agreement with our theoretical
predictions. The observed dependence of the Raman frequencies on the crystal composition is discussed on the
basis of the calculated phonon displacement patterns. The phononic contribution to the static dielectric tensor
is calculated by means of the generalized Lyddane-Sachs-Teller relation. Due to the pronounced dependence of
the optical response on the Ta concentration, lithium niobate tantalate mixed crystals represent a perfect model
system to study the properties of uniaxial mixed ferroelectric materials for application in integrated optics.}},
  author       = {{Rüsing, Michael and Sanna, Simone and Neufeld, Sergej and Berth, Gerhard and Schmidt, Wolf Gero and Zrenner, Artur and Yu, H. and Wang, Y. and Zhang, H.}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  title        = {{{Vibrational properties of LiNb1−xTaxO3 mixed crystals}}},
  doi          = {{10.1103/physrevb.93.184305}},
  year         = {{2016}},
}

@article{4332,
  abstract     = {{LiTaO3 and LiNbO3 crystals are investigated here in a combined experimental and theoretical study that uses Raman spectroscopy in a complete set of scattering geometries and corresponding density-functional theory calculations to provide microscopic information on their vibrational properties. The Raman scattering efficiency is computed from first principles in order to univocally assign the measured Raman peaks to the calculated eigenvectors. Measured and calculated Raman spectra are shown to be in qualitative agreement and confirm the mode assignment by Margueron et al. [J. Appl. Phys. 111, 104105 (2012)], thus finally settling a long debate. While the two crystals show rather similar vibrational properties overall, the E-TO9 mode is markedly different in the two oxides. The deviations are explained by a different anion-cation bond type in LiTaO3 and LiNbO3 crystals.}},
  author       = {{Sanna, Simone and Neufeld, Sergej and Rüsing, Michael and Berth, Gerhard and Zrenner, Artur and Schmidt, Wolf Gero}},
  issn         = {{1098-0121}},
  journal      = {{Physical Review B}},
  number       = {{22}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Raman scattering efficiency in LiTaO3 and LiNbO3 crystals}}},
  doi          = {{10.1103/physrevb.91.224302}},
  volume       = {{91}},
  year         = {{2015}},
}

@article{13520,
  abstract     = {{Atomistic simulations in the framework of the density functional theory have been used to model morphologic and vibrational properties of lithium niobate–lithium tantalate mixed crystals as a function of the [Nb]/[Ta] ratio. Structural parameters such as the crystal volume and the lattice parameters a and c vary roughly linearly from LiTaO3 to LiNbO3, showing only minor deviations from the Vegard behavior. Our ab initio calculations demonstrate that the TO1, TO2 and TO4 vibrational modes become harder with increasing Nb concentration. TO3 becomes softer with increasing Nb content, instead. Furthermore, the investigated zone center A1 -TO phonon modes are characterized by a pronounced stoichiometry dependence. Frequency shifts as large as 30 cm−1 are expected as the [Nb]/[Ta] ratio grows from 0 to 1. Therefore, spectroscopic techniques sensitive to the A1 modes (such as Raman spectroscopy), can be employed for a direct and non-destructive determination of the crystal composition.}},
  author       = {{Sanna, Simone and Riefer, A. and Neufeld, Sergej and Schmidt, Wolf Gero and Berth, Gerhard and Rüsing, Michael and Widhalm, A. and Zrenner, Artur}},
  issn         = {{0015-0193}},
  journal      = {{Ferroelectrics}},
  keywords     = {{Ferroelectrics, vibrational properties, LiNbO3, LiTaO3, mixed crystals}},
  number       = {{1}},
  pages        = {{63--68}},
  title        = {{{Vibrational Fingerprints of LiNbO3-LiTaO3Mixed Crystals}}},
  doi          = {{10.1080/00150193.2013.821893}},
  volume       = {{447}},
  year         = {{2013}},
}

@article{47940,
  abstract     = {{Copper oxide and cobalt oxide (CuO, Co3O4) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation without any postannealing treatment. Both kinds of nanocrystals (NCs) have been prepared using copper nitrate and cobalt nitrate as the starting materials and distilled water as the solvent. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements. The obtained results confirm the presence of the both of oxides nanopowders produced during chemical precipitation using microwave irradiation. A strong emission under UV excitation is obtained from the prepared CuO and Co3O4 nanoparticles. The results show that the nanoparticles have high dispersion and narrow size distribution. The line scans of atomic force microscopy (AFM) images of the nanocrystals (NCs) sprayed on GaAs substrates confirm the results of both X-ray diffraction and transmission electron microscopy. Furthermore, vibrational studies have been carried out using Raman spectroscopic technique. Specific Raman peaks have been observed in the CuO and Co3O4 nanostructures, and the full width at half maximum (FWHM) of the peaks indicates a small particle size of the nanocrystals.}},
  author       = {{Rashad, M. and Rüsing, Michael and Berth, Gerhard and Lischka, K. and Pawlis, A.}},
  issn         = {{1687-4129}},
  journal      = {{Journal of Nanomaterials}},
  keywords     = {{General Materials Science}},
  pages        = {{714853}},
  publisher    = {{Hindawi Limited}},
  title        = {{{CuO and Co3O4 Nanoparticles: Synthesis, Characterizations, and Raman Spectroscopy}}},
  doi          = {{10.1155/2013/714853}},
  volume       = {{2013}},
  year         = {{2013}},
}

@inproceedings{4380,
  abstract     = {{The structural and vibrational properties of lithium niobate (LN) – lithium tantalate (LT) mixed crystals (LNT, LiNb1-xTaxO3) are investigated over the whole composition range by first-principles simulations. The crystal volume grows roughly linearly from LT to LN, whereby the lattice parameters a and c show minor deviations from the Vegard behavior between the end compounds, LiNbO3 and LiTaO3. Our calculations in the framework of the density functional theory show the TO1, TO2 and TO4-modes to become harder with increasing Nb concentration. TO3 becomes softer with increasing Nb content, instead. The frequency shifts of the zone center A1-TO phonon modes for crystals with different compositions are found to be as large as 30 cm-1. Raman spectroscopy, which is sensitive to the A1 modes, can be therefore employed to determine the crystal composition.}},
  author       = {{Sanna, Simone and Riefer, Arthur and Neufeld, Sergej and Schmidt, Wolf Gero and Berth, Gerhard and Widhalm, Alex and Zrenner, Artur}},
  booktitle    = {{Proceedings of ISAF-ECAPD-PFM 2012}},
  keywords     = {{Ferroelectrics, Vibrational properties, LiNbO3, LiTaO3, Mixed Crystals}},
  location     = {{Aveiro, Portugal}},
  title        = {{{Vibrational fingerprints of LiNbO3-LiTaO3 mixed crystals}}},
  year         = {{2012}},
}

@article{4544,
  abstract     = {{The existence of localized vibrational modes both at the positive and at the negative LiNbO3 (0001) surface is demonstrated by means of first-principles calculations and Raman spectroscopy measurements. First, the phonon modes of the crystal bulk and of the (0001) surface are calculated within the density functional theory. In a second step, the Raman spectra of LiNbO3 bulk and of the two surfaces are measured. The phonon modes localized at the two surfaces are found to be substantially different, and are also found to differ from the bulk modes. The calculated and measured frequencies are in agreement within the error of the method. Raman spectroscopy is shown to be sensitive to differences between bulk and surface and between positive and negative surface. It represents therefore an alternative method to determine the surface polarity, which does not exploit the pyroelectric or piezoelectric properties of the material.}},
  author       = {{Sanna, S. and Berth, Gerhard and Hahn, W. and Widhalm, A. and Zrenner, Artur and Schmidt, W. G.}},
  issn         = {{0885-3010}},
  journal      = {{IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control}},
  number       = {{9}},
  pages        = {{1751--1756}},
  publisher    = {{Institute of Electrical and Electronics Engineers (IEEE)}},
  title        = {{{Vibrational properties of the LiNbO3 z-surfaces}}},
  doi          = {{10.1109/tuffc.2011.2012}},
  volume       = {{58}},
  year         = {{2011}},
}

@article{4545,
  abstract     = {{Laser irradiation damage in ZnTe epilayers was analyzed in situ by power-density-dependent and time-resolved micro-Raman spectroscopy. Damage by ablation or compound decomposition on the sample surface was revealed by the decrease of the ZnTe–nLO mode intensity with the increase of laser power density. The appearance of the peaks associated with the stronger crystalline-tellurium modes, tellurium aggregates and second-order Raman scattering at room temperature μ-Raman spectra was observed for higher power densities than 4.4 × 105 W cm−2. The Raman signal time transients of ZnTe–nLO and crystalline-tellurium modes reveal an exponential evolution of the laser irradiation damage and a fast formation of crystalline tellurium aggregates on the layer surface.}},
  author       = {{Wiedemeier, V and Berth, Gerhard and Zrenner, Artur and Larramendi, E M and Woggon, U and Lischka, K and Schikora, D}},
  issn         = {{0268-1242}},
  journal      = {{Semiconductor Science and Technology}},
  number       = {{10}},
  publisher    = {{IOP Publishing}},
  title        = {{{In situ characterization of ZnTe epilayer irradiation via time-resolved and power-density-dependent Raman spectroscopy}}},
  doi          = {{10.1088/0268-1242/26/10/105023}},
  volume       = {{26}},
  year         = {{2011}},
}

@inproceedings{4546,
  abstract     = {{Silicon oxynitride (SiON) layers for telecommunication device application are grown by Plasma Enhanced Chemical Vapor Deposition (PECVD) for various gas compositions of SiH4, N2O and NH3. Processing and annealing effects on the oxynitride films were studied by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM) measurements. By reduction of the silane (SiH4) gas flow and enhancement of the PECVD deposition temperature, the absorption loss due to NH bands can be nearly completely erased. Furthermore the surface roughness can be reduced by decreasing the gas flow and rising the deposition temperature. First waveguide structures are introduced and their characterization is presented.}},
  author       = {{Frers, Torsten and Hett, Thomas and Hilleringmann, Ulrich and Berth, Gerhard and Widhalm, Alex and Zrenner, Artur}},
  booktitle    = {{2011 Semiconductor Conference Dresden}},
  isbn         = {{9781457704314}},
  location     = {{Dresden, Germany}},
  publisher    = {{IEEE}},
  title        = {{{Characterization of SiON integrated waveguides via FTIR and AFM measurements}}},
  doi          = {{10.1109/scd.2011.6068744}},
  year         = {{2011}},
}

@article{4377,
  abstract     = {{Confocal Raman spectroscopy was performed as an archetype imaging method to study the ferroelectric domain structure of periodically poled lithium niobate. More precisely, the linkage out of spatial resolution and spectral information proved itself as very useful. Here a specific modulation of the Raman lines by the local variation of polarity and a non-symmetric measuring-signal across the domain structure were found, which allows for imaging of domain boundaries as well as oppositely orientated domains. The high potential of this method is demonstrated by the visualization of the ferroelectric domain structures based on various phonon modes.}},
  author       = {{Berth, Gerhard and Hahn, Wjatscheslaw and Wiedemeier, Volker and Zrenner, Artur and Sanna, Simone and Schmidt, Wolf Gero}},
  issn         = {{0015-0193}},
  journal      = {{Ferroelectrics}},
  keywords     = {{Raman spectroscopy, ferroelectric domains, LiNbO3, confocal imaging}},
  number       = {{1}},
  pages        = {{44--48}},
  publisher    = {{Informa UK Limited}},
  title        = {{{Imaging of the Ferroelectric Domain Structures by Confocal Raman Spectroscopy}}},
  doi          = {{10.1080/00150193.2011.594774}},
  volume       = {{420}},
  year         = {{2011}},
}