@article{46138, abstract = {{This work reports a fully guided setup for single-mode squeezing on integrated titanium-indiffused periodically poled nonlinear resonators. A continuous-wave laser beam is delivered and the squeezed field is collected by single-mode fibers; up to −3.17(9) dB of useful squeezing is available in fibers. To showcase the usefulness of such a fiber-coupled device, we applied the generated squeezed light in a fiber-based phase sensing experiment, showing a quantum enhancement in the signal-to-noise ratio of 0.35 dB. Moreover, our investigation of the effect of photorefraction on the cavity resonance condition suggests that it causes system instabilities at high powers.}}, author = {{Domeneguetti, Renato and Stefszky, Michael and Herrmann, Harald and Silberhorn, Christine and Andersen, Ulrik L. and Neergaard-Nielsen, Jonas S. and Gehring, Tobias}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{11}}, publisher = {{Optica Publishing Group}}, title = {{{Fully guided and phase locked Ti:PPLN waveguide squeezing for applications in quantum sensing}}}, doi = {{10.1364/ol.486654}}, volume = {{48}}, year = {{2023}}, } @article{35128, abstract = {{Here we demonstrate a new, to the best of our knowledge, type of 3-dB coupler that has an ultra-broadband operational range from 1300 to 1600 nm with low fabrication sensitivity. The overall device size is 800 µm including in/out S-bend waveguides. The coupler is an asymmetric non-uniform directional coupler that consists of two tapered waveguides. One of the coupler arms is shifted by 100 µm in the propagation direction, which results in a more wavelength-insensitive 3-dB response compared to a standard (not shifted) coupler. Moreover, compared to a long adiabatic coupler, we achieved a similar wavelength response at a 16-times-smaller device length. The couplers were fabricated using the silicon nitride platform of Lionix International. We also experimentally demonstrated an optical switch that is made by using two of these couplers in a Mach–Zehnder interferometer configuration. According to experimental results, this optical switch exhibits –10 dB of extinction ratio over the 1500–1600 nm wavelength range. Our results indicate that this new type of coupler holds great promise for various applications, including optical imaging, telecommunications, and reconfigurable photonic processors where compact, fabrication-tolerant, and wavelength-insensitive couplers are essential.}}, author = {{Nikbakht, Hamed and Khoshmehr, Mohammad Talebi and van Someren, Bob and Teichrib, Dieter and Hammer, Manfred and Förstner, Jens and Akca, B. Imran}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_waveguide}}, number = {{2}}, pages = {{207}}, publisher = {{Optica Publishing Group}}, title = {{{Asymmetric, non-uniform 3-dB directional coupler with 300-nm bandwidth and a small footprint}}}, doi = {{10.1364/ol.476537}}, volume = {{48}}, year = {{2022}}, } @article{29075, abstract = {{We study a double-scattering coherent mechanism of negative polarization (NP) near opposition that is observed for powder-like surfaces. The problem is solved numerically for absorbing structures with irregular constituents, cubes, spheres, and ellipsoids larger than the wavelength of incident light. Our simulations show that double scattering between two random irregular particles shows weak NP. Adding one more particle significantly increases the relative contribution of double scattering which enhances NP. Simulations with regular shapes and controlled geometric parameters show that the interference mechanism is sensitive to the geometry of the scattering system and can also result in no polarization or even strong enhancement of positive polarization at backscattering.}}, author = {{Alhaddad, Samer and Grynko, Yevgen and Farheen, Henna and Förstner, Jens}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_scattering}}, number = {{1}}, pages = {{58}}, title = {{{Numerical analysis of the coherent mechanism producing negative polarization at backscattering from systems of absorbing particles}}}, doi = {{10.1364/ol.444953}}, volume = {{47}}, year = {{2022}}, } @article{32148, author = {{Gao, Xinghui and Hu, Wei and Schumacher, Stefan and Ma, Xuekai}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{13}}, pages = {{3235--3238}}, publisher = {{Optica Publishing Group}}, title = {{{Unidirectional vortex waveguides and multistable vortex pairs in polariton condensates}}}, doi = {{10.1364/ol.457724}}, volume = {{47}}, year = {{2022}}, } @article{19507, author = {{Barkhausen, Franziska and Schumacher, Stefan and Ma, Xuekai}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{pc2-ressources}}, title = {{{Multistable circular currents of polariton condensates trapped in ring potentials}}}, doi = {{10.1364/ol.386250}}, year = {{2020}}, } @article{20585, author = {{Ma, Xuekai and Kartashov, YV and Ferrando, A and Schumacher, Stefan}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{19}}, pages = {{5311--5314}}, title = {{{Topological edge states of nonequilibrium polaritons in hollow honeycomb arrays.}}}, doi = {{10.1364/ol.405844}}, volume = {{45}}, year = {{2020}}, } @article{20587, author = {{Barkhausen, F and Schumacher, Stefan and Ma, Xuekai}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{5}}, pages = {{1192--1195}}, title = {{{Multistable circular currents of polariton condensates trapped in ring potentials.}}}, doi = {{10.1364/ol.386250}}, volume = {{45}}, year = {{2020}}, } @article{20586, author = {{Ma, Xuekai and Kartashov, YV and Kavokin, A and Schumacher, Stefan}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{20}}, pages = {{5700--5703}}, title = {{{Chiral condensates in a polariton hexagonal ring.}}}, doi = {{10.1364/ol.405400}}, volume = {{45}}, year = {{2020}}, } @article{26225, author = {{Santandrea, Matteo and Stefszky, Michael and Silberhorn, Christine}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, title = {{{General framework for the analysis of imperfections in nonlinear systems}}}, doi = {{10.1364/ol.44.005398}}, year = {{2019}}, } @article{20578, author = {{Driben, R and Ma, Xuekai and Schumacher, Stefan and Meier, Torsten}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{6}}, pages = {{1327--1330}}, title = {{{Bloch oscillations of multidimensional dark soliton wave packets and light bullets}}}, doi = {{10.1364/ol.44.001327}}, volume = {{44}}, year = {{2019}}, } @article{4324, abstract = {{We study the dependence of the intensity and linear polarization of light scattered by isolated particles with the compact irregular shape on their size using the discontinuous Galerkin time domain numerical method. The size parameter of particles varies in the range of X = 10 to 150, and the complex refractive index is m = 1.5 + 0i. Our results show that the backscattering negative polarization branch weakens monotonously, but does not disappear at large sizes, up to the geometrical optics regime, and can be simulated without accounting for wave effects. The intensity backscattering surge becomes narrower with increasing particle size. For X = 150, the surge width is several degrees.}}, author = {{Grynko, Yevgen and Shkuratov, Yuriy and Förstner, Jens}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_scattering}}, number = {{15}}, pages = {{3562}}, publisher = {{The Optical Society}}, title = {{{Intensity surge and negative polarization of light from compact irregular particles}}}, doi = {{10.1364/ol.43.003562}}, volume = {{43}}, year = {{2018}}, } @article{3843, abstract = {{We simulate light scattering by random irregular particles that have dimensions much larger than the wavelength of incident light at the size parameter of 𝑋=200 using the discontinuous Galerkin time domain method. A comparison of the DGTD solution for smoothly faceted particles with that obtained with a geometric optics model shows good agreement for the scattering angle curves of intensity and polarization. If a wavelength-scale surface roughness is introduced, diffuse scattering at rough interface results in smooth and featureless curves for all scattering matrix elements which is consistent with the laboratory measurements of real samples.}}, author = {{Grynko, Yevgen and Shkuratov, Yuriy and Förstner, Jens}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_scattering}}, number = {{15}}, pages = {{3491--3493}}, publisher = {{The Optical Society}}, title = {{{Light scattering by irregular particles much larger than the wavelength with wavelength-scale surface roughness}}}, doi = {{10.1364/ol.41.003491}}, volume = {{41}}, year = {{2016}}, } @article{40393, author = {{Cavanna, Andrea and Just, Felix and Sharapova, Polina and Taheri, Michael and Leuchs, Gerd and Chekhova, Maria V.}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{3}}, publisher = {{The Optical Society}}, title = {{{Tunable optical parametric generator based on the pump spatial walk-off}}}, doi = {{10.1364/ol.41.000646}}, volume = {{41}}, year = {{2016}}, } @article{3894, abstract = {{We show how to optically connect guiding layers at different elevations in a 3-D integrated photonic circuit. Transfer of optical power carried by planar, semi-guided waves is possible without reflections or radiation losses, and over large vertical distances. This functionality is realized through simple step-like folds of high-contrast dielectric slab waveguides, in combination with oblique wave incidence, and fulfilling a resonance condition. Radiation losses vanish, and polarization conversion is suppressed for TE wave incidence beyond certain critical angles. This can be understood by fundamental arguments resting on a version of Snell’s law. The two 90° corners of a step act as identical partial reflectors in a Fabry–Perot-like resonator setup. By selecting the step height, i.e., the distance between the reflectors, one realizes resonant states with full transmission. Rigorous quasi-analytical simulations for typical silicon/silica parameters demonstrate the functioning. Combinations of several step junctions can lead to other types of optical on-chip connects, e.g., U-turn- or bridge-like configurations.}}, author = {{Hammer, Manfred and Hildebrandt, Andre and Förstner, Jens}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_waveguide}}, number = {{16}}, pages = {{3711--3714}}, publisher = {{The Optical Society}}, title = {{{How planar optical waves can be made to climb dielectric steps}}}, doi = {{10.1364/ol.40.003711}}, volume = {{40}}, year = {{2015}}, } @article{3896, abstract = {{We study the formation of subwavelength solitons in binary metal-dielectric lattices. We show that the transverse modulation of the lattice constant breaks the fundamental plasmonic band and suppresses the discrete diffraction of surface plasmon waves. New types of plasmonic solitons are found, and their characteristics are analyzed. We also demonstrate the existence of photonic-plasmonic vector solitons and elucidate their propagation properties.}}, author = {{Kou, Yao and Förstner, Jens}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, keywords = {{tet_topic_polariton}}, number = {{6}}, pages = {{851--854}}, publisher = {{The Optical Society}}, title = {{{Subwavelength binary plasmonic solitons}}}, doi = {{10.1364/ol.40.000851}}, volume = {{40}}, year = {{2015}}, } @article{22947, author = {{Oreshnikov, I. and Driben, R. and Yulin, A. V.}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, title = {{{Interaction of high-order solitons with external dispersive waves}}}, doi = {{10.1364/ol.40.005554}}, year = {{2015}}, } @article{63735, author = {{Kaczmarek, Krzysztof T. and Saunders, Dylan J. and Sprague, Michael R. and Kolthammer, W. Steven and Feizpour, Amir and Ledingham, Patrick M. and Brecht, Benjamin and Poem, Eilon and Walmsley, Ian A. and Nunn, Joshua}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{23}}, publisher = {{Optica Publishing Group}}, title = {{{Ultrahigh and persistent optical depths of cesium in Kagomé-type hollow-core photonic crystal fibers}}}, doi = {{10.1364/ol.40.005582}}, volume = {{40}}, year = {{2015}}, } @article{13930, author = {{Oreshnikov, I. and Driben, R. and Yulin, A. V.}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{21}}, title = {{{Weak and strong interactions between dark solitons and dispersive waves}}}, doi = {{10.1364/ol.40.004871}}, volume = {{40}}, year = {{2015}}, } @article{13924, author = {{Oreshnikov, I. and Driben, R. and Yulin, A. V.}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{21}}, title = {{{Weak and strong interactions between dark solitons and dispersive waves}}}, doi = {{10.1364/ol.40.004871}}, volume = {{40}}, year = {{2015}}, } @article{13923, author = {{Oreshnikov, I. and Driben, R. and Yulin, A. V.}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{23}}, title = {{{Interaction of high-order solitons with external dispersive waves}}}, doi = {{10.1364/ol.40.005554}}, volume = {{40}}, year = {{2015}}, }