TY - JOUR
AB - We study the DC conductivity in potassium titanyl phosphate (KTiOPO4, KTP) and its isomorphs KTiOAsO4 (KTA) and Rb1%K99%TiOPO4 (RKTP) and introduce a method by which to reduce the overall ionic conductivity in KTP by a potassium nitrate treatment. Furthermore, we create so-called gray tracking in KTP and investigate the ionic conductivity in theses areas. A local unintended reduction of the ionic conductivity is observed in the gray-tracked regions, which also induce additional optical absorption in the material. We show that a thermal treatment in an oxygen-rich atmosphere removes the gray tracking and brings the ionic conductivity as well as the optical transmission back to the original level. These studies can help to choose the best material and treatment for specific applications.
AU - Padberg, Laura
AU - Quiring, Viktor
AU - Bocchini, Adriana
AU - Santandrea, Matteo
AU - Gerstmann, Uwe
AU - Schmidt, Wolf Gero
AU - Silberhorn, Christine
AU - Eigner, Christof
ID - 33484
JF - Crystals
SN - 2073-4352
TI - DC Ionic Conductivity in KTP and Its Isomorphs: Properties, Methods for Suppression, and Its Connection to Gray Tracking
VL - 12
ER -
TY - JOUR
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Silberhorn, Christine
ID - 26218
JF - Journal of Optics
SN - 2040-8978
TI - General analytic theory of classical collinear three-wave mixing in a monolithic cavity
ER -
TY - JOUR
AU - Bartnick, Moritz
AU - Santandrea, Matteo
AU - Höpker, Jan Philipp
AU - Thiele, Frederik
AU - Ricken, Raimund
AU - Quiring, Viktor
AU - Eigner, Christof
AU - Herrmann, Harald
AU - Silberhorn, Christine
AU - Bartley, Tim
ID - 26221
JF - Physical Review Applied
SN - 2331-7019
TI - Cryogenic Second-Harmonic Generation in Periodically Poled Lithium Niobate Waveguides
ER -
TY - CONF
AB - We present a frequency multimode integrated SU (1,1) interferometer with a polarization converter and strong signal-idler photon correlations. Phase sensitivity below the shot noise limit is demonstrated, various filtering and seeding strategies are discussed.
AU - Ferreri, A.
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Luo, Kai Hong
AU - Herrmann, Harald
AU - Silberhorn, Christine
AU - Sharapova, Polina
ID - 40374
T2 - Conference on Lasers and Electro-Optics
TI - Multimode integrated SU(1,1) interferometer
ER -
TY - JOUR
AU - Gil López, Jano
AU - Santandrea, Matteo
AU - Roland, Ganaël
AU - Brecht, Benjamin
AU - Eigner, Christof
AU - Ricken, Raimund
AU - Quiring, Viktor
AU - Silberhorn, Christine
ID - 22770
JF - New Journal of Physics
SN - 1367-2630
TI - Improved non-linear devices for quantum applications
ER -
TY - JOUR
AB - Nonlinear SU(1,1) interferometers are fruitful and promising tools for spectral engineering and precise measurements with phase sensitivity below the classical bound. Such interferometers have been successfully realized in bulk and fiber-based configurations. However, rapidly developing integrated technologies provide higher efficiencies, smaller footprints, and pave the way to quantum-enhanced on-chip interferometry. In this work, we theoretically realised an integrated architecture of the multimode SU(1,1) interferometer which can be applied to various integrated platforms. The presented interferometer includes a polarization converter between two photon sources and utilizes a continuous-wave (CW) pump. Based on the potassium titanyl phosphate (KTP) platform, we show that this configuration results in almost perfect destructive interference at the output and supersensitivity regions below the classical limit. In addition, we discuss the fundamental difference between single-mode and highly multimode SU(1,1) interferometers in the properties of phase sensitivity and its limits. Finally, we explore how to improve the phase sensitivity by filtering the output radiation and using different seeding states in different modes with various detection strategies.
AU - Ferreri, Alessandro
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Luo, Kai Hong
AU - Herrmann, Harald
AU - Silberhorn, Christine
AU - Sharapova, Polina R.
ID - 26077
JF - Quantum
SN - 2521-327X
TI - Spectrally multimode integrated SU(1,1) interferometer
ER -
TY - JOUR
AU - Luo, Kai Hong
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Sperling, Jan
AU - Massaro, Marcello
AU - Ferreri, Alessandro
AU - Sharapova, Polina
AU - Herrmann, Harald
AU - Silberhorn, Christine
ID - 26889
JF - Physical Review A
SN - 2469-9926
TI - Quantum optical coherence: From linear to nonlinear interferometers
ER -
TY - JOUR
AB - 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.
AU - Brockmeier, Julian
AU - Mackwitz, Peter Walter Martin
AU - Rüsing, Michael
AU - Eigner, Christof
AU - Padberg, Laura
AU - Santandrea, Matteo
AU - Silberhorn, Christine
AU - Zrenner, Artur
AU - Berth, Gerhard
ID - 23826
JF - Crystals
SN - 2073-4352
TI - Non-Invasive Visualization of Ferroelectric Domain Structures on the Non-Polar y-Surface of KTiOPO4 via Raman Imaging
ER -
TY - JOUR
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Roeland, Ganaël
AU - Silberhorn, Christine
ID - 26223
JF - Optics Express
SN - 1094-4087
TI - Interferometric method for determining the losses of spatially multi-mode nonlinear waveguides based on second harmonic generation
ER -
TY - JOUR
AU - Stefszky, Michael
AU - Santandrea, Matteo
AU - vom Bruch, Felix
AU - Krapick, S.
AU - Eigner, Christof
AU - Ricken, R.
AU - Quiring, V.
AU - Herrmann, Harald
AU - Silberhorn, Christine
ID - 22771
JF - Optics Express
SN - 1094-4087
TI - Waveguide resonator with an integrated phase modulator for second harmonic generation
ER -
TY - JOUR
AB - The characterisation of loss in optical waveguides is essential in understanding the performance of these devices and their limitations. Whilst interferometric-based methods generally provide the best results for low-loss waveguides, they are almost exclusively used to provide characterization in cases where the waveguide is spatially single-mode. Here, we introduce a Fabry-Pérot-based scheme to estimate the losses of a nonlinear (birefringent or quasi-phase matched) waveguide at a wavelength where it is multi-mode. The method involves measuring the generated second harmonic power as the pump wavelength is scanned over the phase matching region. Furthermore, it is shown that this method allows one to infer the losses of different second harmonic spatial modes by scanning the pump field over the separated phase matching spectra. By fitting the measured phase matching spectra from different titanium indiffused lithium niobate waveguides to the model presented in this paper, it is shown that one can estimate the second harmonic losses of a single spatial-mode, at wavelengths where the waveguides are spatially multi-mode.
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Roeland, Ganaël
AU - Silberhorn, Christine
ID - 38051
IS - 4
JF - Optics Express
KW - Atomic and Molecular Physics
KW - and Optics
SN - 1094-4087
TI - Interferometric method for determining the losses of spatially multi-mode nonlinear waveguides based on second harmonic generation.
VL - 28
ER -
TY - JOUR
AU - Eigner, Christof
AU - Padberg, Laura
AU - Santandrea, Matteo
AU - Herrmann, Harald
AU - Brecht, Benjamin
AU - Silberhorn, Christine
ID - 21025
IS - 22
JF - Optics Express
SN - 1094-4087
TI - Spatially single mode photon pair source at 800 nm in periodically poled Rubidium exchanged KTP waveguides
VL - 28
ER -
TY - JOUR
AU - Padberg, Laura
AU - Santandrea, Matteo
AU - Rüsing, Michael
AU - Brockmeier, Julian
AU - Mackwitz, Peter
AU - Berth, Gerhard
AU - Zrenner, Artur
AU - Eigner, Christof
AU - Silberhorn, Christine
ID - 25920
JF - Optics Express
SN - 1094-4087
TI - Characterisation of width-dependent diffusion dynamics in rubidium-exchanged KTP waveguides
ER -
TY - JOUR
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Roeland, Ganaël
AU - Silberhorn, Christine
ID - 26224
JF - New Journal of Physics
SN - 1367-2630
TI - Characterisation of fabrication inhomogeneities in Ti:LiNbO3 waveguides
ER -
TY - JOUR
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Silberhorn, Christine
ID - 26225
JF - Optics Letters
SN - 0146-9592
TI - General framework for the analysis of imperfections in nonlinear systems
ER -
TY - JOUR
AU - Santandrea, Matteo
AU - Stefszky, Michael
AU - Ansari, Vahid
AU - Silberhorn, Christine
ID - 26226
JF - New Journal of Physics
SN - 1367-2630
TI - Fabrication limits of waveguides in nonlinear crystals and their impact on quantum optics applications
ER -
TY - JOUR
AU - Luo, Kai-Hong
AU - Ansari, Vahid
AU - Massaro, Marcello
AU - Santandrea, Matteo
AU - Eigner, Christof
AU - Ricken, Raimund
AU - Herrmann, Harald
AU - Silberhorn, Christine
ID - 26237
JF - Optics Express
SN - 1094-4087
TI - Counter-propagating photon pair generation in a nonlinear waveguide
ER -
TY - JOUR
AU - Luo, Kai Hong
AU - Ansari, Vahid
AU - Massaro, Marcello
AU - Santandrea, Matteo
AU - Eigner, Christof
AU - Ricken, Raimund
AU - Herrmann, Harald
AU - Silberhorn, Christine
ID - 26052
JF - Optics Express
SN - 1094-4087
TI - Counter-propagating photon pair generation in a nonlinear waveguide
ER -
TY - JOUR
AU - Eigner, Christof
AU - Santandrea, Matteo
AU - Padberg, Laura
AU - Volk, Martin F.
AU - Rüter, Christian E.
AU - Herrmann, Harald
AU - Kip, Detlef
AU - Silberhorn, Christine
ID - 9614
JF - Optics Express
SN - 1094-4087
TI - Periodically poled ridge waveguides in KTP for second harmonic generation in the UV regime
ER -
TY - JOUR
AU - Ansari, V.
AU - Roccia, E.
AU - Santandrea, Matteo
AU - Doostdar, M.
AU - Eigner, Christof
AU - Padberg, Laura
AU - Gianani, I.
AU - Sbroscia, M.
AU - Donohue, J. M.
AU - Mancino, L.
AU - Barbieri, M.
AU - Silberhorn, Christine
ID - 9619
JF - Optics Express
SN - 1094-4087
TI - Heralded generation of high-purity ultrashort single photons in programmable temporal shapes
ER -