BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:A.V. Andrianov DTSTART:20240907T092000Z DTEND:20240907T110000Z DTSTAMP:20260423T040007Z UID:QOART/31 DESCRIPTION:Title: K err squeezing in optical waveguides and its use to improve the sensitivity of interferometers\nby A.V. Andrianov as part of Quantum Optics and R elated Topics\n\n\nAbstract\nSqueezed light is one of the key resources of photonic quantum technology. Among the various applications of squeezed l ight states\, measurement beyond the standard quantum limit is one of the most prominent. Squeezed light is regularly used in large-scale gravitatio nal wave detectors. Among the various nonlinear interactions that can prod uce squeezing\, the optical Kerr effect is particularly interesting becaus e it can potentially be implemented in a wide variety of materials and arr angements. It does not require phase matching\, and one can use optical wa veguides to achieve long interaction lengths. The amount of squeezing can reach significant levels due to the tight confinement in the fibres (and t hus high intensity). However\, the advantages of generating bright squeeze d states in third-order nonlinear media are somewhat masked by difficultie s in using them for applications such as interferometry\, because the unce rtainty distribution in phase\nspace for these states is tilted with respe ct to both phase and amplitude quadrature. In this talk\, we review variou s techniques for generating squeezed light in optical waveguides (and in p articular optical fibres)\, and discuss a novel approach to overcome diffi culties in applying Kerr-squeezed light to quantum-enhanced interferometry . One popular approach to work with the Kerr-squeezed tilted states is to create a polarisation-squeezed state by combining two such states in ortho gonal polarisations of the same spatial mode. In a polarisation squeezed s tate the fluctuations of a particular Stokes parameter are smaller than in a coherent state with the same mean polarisation state. In such setups\, it is important to use pulsed light and to protect the polarisation modes from cross-Kerr interaction by temporally separating the pulses. This can be done efficiently and in a very stable manner using polarisation-maintai ning fibres and/or polarisation-sensitive group delay compensators. We rep ort on a very stable approach to build an all-fiber setup for the generati on of Kerr-squeezed light states based on polarisation-maintaining silica fibers [1]\, and on a demonstration of interferometric sensitivity enhance ment beyond the shot noise limit using these states [2]. We also present t he first experimental observation of squeezed light generation in chalcoge nide fibres. Chalcogenide glass fibres have 3-5 orders of magnitude higher nonlinearity than standard\nsilica fibres. They also exhibit a wide range of mid-IR transparency. This stimulates the study of chalcogenide (and ot her soft highly nonlinear glasses such as tellurite) as it promotes the\nd evelopment of non-classical light sources in an extended wavelength range that is not readily accessible with current technologies. In the talk we a lso discuss some aspects of numerical modelling and optimisation [3] of sq ueezed light generation in nonlinear waveguides made of different material s (silica\, soft tellurite and chalcogenide glasses)\, paying special atte ntion to parasitic effects such as Raman scattering.\n\n[1] N. Kalinin\, T . Dirmeier\, A. A. Sorokin\, E. A. Anashkina\, L. L. Sánchez‐Soto\, J. F. Corney\, G. Leuchs\, and A. V. Andrianov\, "Observation of Robust Polar ization Squeezing via the Kerr Nonlinearity in an Optical Fiber\," Adv Qua ntum Tech 6(3)\, 2200143 (2023).\n\n[2] N. Kalinin\, T. Dirmeier\, A. A. S orokin\, E. A. Anashkina\, L. L. Sánchez-Soto\, J. F. Corney\, G. Leuchs\ , and A. V. Andrianov\, "Quantum-enhanced interferometer using Kerr squeez ing\," Nanophotonics 12(14)\, 2945–2952 (2023).\n\n[3] A. V. Andrianov\, N. A. Kalinin\, A. A. Sorokin\, E. A. Anashkina\, L. L. Sánchez-Soto\, J . F. Corney\, and G. Leuchs\, "Optimizing the generation of polarization s queezed light in nonlinear optical fibers driven by femtosecond pulses\," Opt. Express 31(1)\, 765 (2023).\n LOCATION:https://researchseminars.org/talk/QOART/31/ END:VEVENT END:VCALENDAR