arXiv - PHYS - Optics最新文献

{"title":"Resonant EO combs: Beyond the standard phase noise model of frequency combs","authors":"Holger R. Heebøll, Pooja Sekhar, Jasper Riebesehl, Aleksandr Razumov, Matt Heyrich, Michael Galili, Francesco Da Ros, Scott Diddams, Darko. Zibar","doi":"arxiv-2409.06570","DOIUrl":"https://doi.org/arxiv-2409.06570","url":null,"abstract":"A resonant electro-optic (EO) frequency comb is generated through\u0000electro-optic modulation of laser light within an optical resonator. Compared\u0000to cavity-less EO combs generated in a single pass through a modulator,\u0000resonant EO combs can produce broader spectra with lower radio frequency (RF)\u0000power and offer a measure of noise filtering beyond the cavity's linewidth.\u0000Understanding, measuring, and suppressing the sources of phase noise in\u0000resonant EO combs is crucial for their applications in metrology,\u0000astrophotonics, optical clock generation, and fiber-optic communication.\u0000According to the standard phase noise model of frequency combs, only two\u0000variables - the common mode offset and repetition rate phase noise - are needed\u0000to fully describe the phase noise of comb lines. However, in this work we\u0000demonstrate analytically, numerically, and experimentally that this standard\u0000model breaks down for resonant EO combs at short timescales (high frequencies)\u0000and under certain comb parameters. Specifically, a third phase noise component\u0000emerges. Consequently, resonant EO combs feature qualitatively different phase\u0000noise from their cavity-less counterparts and may not exhibit the anticipated\u0000noise filtering. A more complete description of the deviations from the\u0000standard phase noise model is critical to accurately predict the performance of\u0000frequency combs. The description presented here paves the way for improved\u0000designs tailored to applications such as super-continuum generation and optical\u0000communication.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attosecond Inner-Shell Lasing at Angstrom Wavelengths","authors":"Thomas M. Linker, Aliaksei Halavanau, Thomas Kroll, Andrei Benediktovitch, Yu Zhang, Yurina Michine, Stasis Chuchurka, Zain Abhari, Daniele Ronchetti, Thomas Fransson, Clemens Weninger, Franklin D. Fuller, Andy Aquila, Roberto Alonso-Mori, Sebastien Boutet, Marc W. Guetg, Agostino Marinelli, Alberto A. Lutman, Makina Yabashi, Ichiro Inoue, Taito Osaka, Jumpei Yamada, Yuichi Inubushi, Gota Yamaguchi, Toru Hara, Ganguli Babu, Devashish Salpekar, Farheen N. Sayed, Pulickel M. Ajayan, Jan Kern, Junko Yano, Vittal K. Yachandra, Matthias F. Kling, Claudio Pellegrini, Hitoki Yoneda, Nina Rohringer, Uwe Bergmann","doi":"arxiv-2409.06914","DOIUrl":"https://doi.org/arxiv-2409.06914","url":null,"abstract":"Since the invention of the laser nonlinear effects such as filamentation,\u0000Rabi-cycling and collective emission have been explored in the optical regime\u0000leading to a wide range of scientific and industrial applications. X-ray free\u0000electron lasers (XFELs) have led to the extension of many optical techniques to\u0000X-rays for their advantages of angstrom scale spatial resolution and elemental\u0000specificity. One such example is XFEL driven population inversion of 1s core\u0000hole states resulting in inner-shell K${alpha}$ (2p to 1s) X-ray lasing in\u0000elements ranging from neon to copper, which has been utilized for nonlinear\u0000spectroscopy and development of next generation X-ray laser sources. Here we\u0000show that strong lasing effects, similar to those observed in the optical\u0000regime, can occur at 1.5 to 2.1 angstrom wavelengths during high intensity (>\u0000${10^{19}}$ W/cm${^{2}}$) XFEL driven inner-shell lasing and superfluorescence\u0000of copper and manganese. Depending on the temporal substructure of the XFEL\u0000pump pulses, the resulting inner-shell X-ray laser pulses can exhibit strong\u0000spatial inhomogeneities as well as spectral inhomogeneities and broadening.\u0000Through 3D Maxwell Bloch theory we show that the observed spatial\u0000inhomogeneities result from X-ray filamentation, and that the spectral\u0000broadening is driven by Rabi cycling with sub-femtosecond periods. These\u0000findings indicate that we have generated Angstrom-wavelength x-ray pulses\u0000(containing ${10^{6}}$ - ${10^{8}}$ photons) in the strong lasing regime, some\u0000of them with pulse lengths of less than 100 attoseconds.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modal Statistics in Mode-Division-Multiplexed Systems using Mode Scramblers","authors":"Anirudh Vijay, Oleksiy Krutko, Rebecca Refaee, Joseph M. Kahn","doi":"arxiv-2409.06908","DOIUrl":"https://doi.org/arxiv-2409.06908","url":null,"abstract":"Typical multi-mode fibers exhibit strong intra-group mode coupling and weak\u0000inter-group mode coupling. Mode scramblers can be inserted at periodic\u0000intervals to enhance inter-group coupling. The deterministic mode coupling of\u0000the mode scramblers, in concert with the random mode coupling of the fiber\u0000spans, can effect strong random mode coupling between all modes. This reduces\u0000both modal dispersion and mode-dependent loss, thereby decreasing receiver\u0000complexity and increasing link capacity. In this paper, we analyze the effect\u0000of mode scramblers on end-to-end group-delay and mode-dependent loss standard\u0000deviations in long-haul multi-mode fiber links. We develop analytical tools in\u0000the generalized Jones and Stokes representations. We propose design criteria\u0000for mode scramblers that ensure strong end-to-end coupling: the\u0000mode-group-averaged power coupling matrix should be primitive and its\u0000non-dominant eigenvalues should be near zero. We argue that when the mode\u0000scramblers satisfy these criteria, the probability distribution of the system\u0000transfer matrix asymptotically approaches that of a system with strong random\u0000mode coupling between all modes. Consequently, group-delay and mode-dependent\u0000loss standard deviations become sufficient statistics of the eigenvalues of the\u0000group-delay operator and the modal gains operator, respectively. We also show\u0000that under certain conditions on the uncoupled group delays, it is possible to\u0000design self-compensating mode scramblers to reduce group delay accumulation\u0000below that of standard strong random coupling.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planar Bragg microcavities with monolayer WS$_2$ for strong exciton-photon coupling","authors":"A. O. Mikhin, A. A. Seredin, R. S. Savelev, D. N. Krizhanovskii, A. K. Samusev, V. Kravtsov","doi":"arxiv-2409.06335","DOIUrl":"https://doi.org/arxiv-2409.06335","url":null,"abstract":"We propose and numerically investigate a novel compact planar microcavity\u0000design based on a high-index dielectric slab waveguide with embedded monolayer\u0000semiconductor. In comparison to more traditional vertical Bragg microcavities,\u0000our design relies on the transmission of guided optical modes and achieves\u0000strong exciton-photon coupling in a chip-compatible and compact geometry with\u0000sub-100 nm thickness. We show that Rabi splitting values of more than 70 meV\u0000can be obtained in planar microcavities with the total length below 5 um.\u0000Further, we reveal the dependence of Rabi splitting on the dimensions of the\u0000structure and explain it with a simple theoretical model. Our results\u0000contribute towards the development of novel compact 2D semiconductor-based\u0000components for integrated photonic circuits.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A spiral sampling method for calculating the complex orbital angular momentum spectrum","authors":"Zheng Han, Bowen Yang, Xiao Chen, Yiquan Wang","doi":"arxiv-2409.06430","DOIUrl":"https://doi.org/arxiv-2409.06430","url":null,"abstract":"OAM spectrum reflects the OAM component included in measured light field\u0000which is crucial in OAM -based application. However, traditional\u0000definition-based OAM spectrum algorithm is extraordinary time-consuming and\u0000limited to prior knowledge severely. To overcome it, in this paper, we propose\u0000a novel method to calculate the complex spectrum. After spiral sampling and\u0000Fourier transform, one can retrieve the radial coefficient of arbitrary OAM\u0000component by proper filtering and inverse Fourier transform. The simulation\u0000results reveal that the Mean Absolute Error (MAE) between retrieved one and\u0000target could reach at 0.0221 and 0.0199 on average for amplitude and phase\u0000respectively after normalized. This method could provide a powerful tool for\u0000future OAM-based and application.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamic model for laser swelling","authors":"Nikita Bityurin, Natalia Sapogova","doi":"arxiv-2409.06370","DOIUrl":"https://doi.org/arxiv-2409.06370","url":null,"abstract":"The evolution of surface layers of a glassy material heated by a laser pulse\u0000above the glass transition temperature and cooled by heat diffusion is\u0000considered as the flow of a stretchable viscous fluid. The strong dependence of\u0000viscosity on temperature and pressure leads to the appearance of a hump with\u0000reduced density. This hydrodynamic model for laser swelling is formulated in\u0000general form. We present a 1D solution for laser swelling of a thin glassy\u0000polymer film on a strongly thermally conductive substrate for laser pulses long\u0000enough that the sound confinement effect can be neglected. It is shown that\u0000within this condition the evolution of the film thickness over time can be\u0000addressed using a second-order ordinary differential equation. It is also shown\u0000that in some cases this equation can be reduced to a first-order differential\u0000equation resembling the phenomenological equation of the previously published\u0000relaxation model of laser swelling. The main features of the dependence of\u0000laser swelling on laser fluence, namely the threshold at low fluencies and\u0000saturation at high fluencies, have been clarified allowing for the dependence\u0000of viscosity on pressure, which was not taken into account in the previous\u0000theoretical studies of laser swelling. Typical regimes of the film thickness\u0000evolution are considered and compared to existing experimental data.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Neural Engine for Solving Scientific Partial Differential Equations","authors":"Yingheng TangJackie, Ruiyang ChenJackie, Minhan LouJackie, Jichao FanJackie, Cunxi YuJackie, Andy NonakaJackie, ZhiJackie, Yao, Weilu Gao","doi":"arxiv-2409.06234","DOIUrl":"https://doi.org/arxiv-2409.06234","url":null,"abstract":"Solving partial differential equations (PDEs) is the cornerstone of\u0000scientific research and development. Data-driven machine learning (ML)\u0000approaches are emerging to accelerate time-consuming and computation-intensive\u0000numerical simulations of PDEs. Although optical systems offer high-throughput\u0000and energy-efficient ML hardware, there is no demonstration of utilizing them\u0000for solving PDEs. Here, we present an optical neural engine (ONE) architecture\u0000combining diffractive optical neural networks for Fourier space processing and\u0000optical crossbar structures for real space processing to solve time-dependent\u0000and time-independent PDEs in diverse disciplines, including Darcy flow\u0000equation, the magnetostatic Poisson equation in demagnetization, the\u0000Navier-Stokes equation in incompressible fluid, Maxwell's equations in\u0000nanophotonic metasurfaces, and coupled PDEs in a multiphysics system. We\u0000numerically and experimentally demonstrate the capability of the ONE\u0000architecture, which not only leverages the advantages of high-performance\u0000dual-space processing for outperforming traditional PDE solvers and being\u0000comparable with state-of-the-art ML models but also can be implemented using\u0000optical computing hardware with unique features of low-energy and highly\u0000parallel constant-time processing irrespective of model scales and real-time\u0000reconfigurability for tackling multiple tasks with the same architecture. The\u0000demonstrated architecture offers a versatile and powerful platform for\u0000large-scale scientific and engineering computations.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inverse design of Mie resonators with minimal backscattering","authors":"Vladimir Igoshin, Alexey Kokhanovskiy, Mihail Petrov","doi":"arxiv-2409.06331","DOIUrl":"https://doi.org/arxiv-2409.06331","url":null,"abstract":"Manipulation and engineering of light scattering by resonant nanostructures\u0000is one of the central problems in optics and photonics. In this work, we\u0000theoretically study the effect of suppressed back-scattering of dielectric\u0000nanoantenna. We employed covariance matrix adaptation evolution strategy to\u0000identify the geometries of circular dielectric structures with minimized\u0000backward scattering cross section. Zero back-scattering is achieved due to\u0000generalized Kerker effect and multipole cancellation condition. We found a set\u0000of geometries and shapes of the nanoantenna having back-scattering intensity\u0000close to zero. With help of clustering algorithms, all the found geometries\u0000fall separated into several groups according to their multipolar content. While\u0000the optical properties of scatterers in each group were similar due to similar\u0000multipolar content, their shapes can be significantly different which stresses\u0000the ambiguity of free-form optimization problem. We believe that the obtained\u0000results and found possible classes on generalized Kerker nanoantenna can help\u0000in designing nanophotonic structures such as antireflective metasurfaces.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic quadrupole dichroism in isotropic medium","authors":"A. A. Fomin, G. G. Kozlov, M. V. Petrenko, M. Yu. Petrov, D. S. Smirnov, V. S. Zapasskii","doi":"arxiv-2409.05411","DOIUrl":"https://doi.org/arxiv-2409.05411","url":null,"abstract":"For an isotropic medium, a magnetic field applied in the Voigt geometry\u0000affects the optical properties in the second order only, so its effect is much\u0000weaker than in the Faraday geometry. In this work, we show that, under resonant\u0000excitation well beyond the linear regime, the situation changes drastically: A\u0000small magnetic linear anisotropy considerably increases, and an even stronger\u0000new quadrupole dichroism emerges. The latter manifests itself as\u000090{deg}-periodic azimuthal dependence of transmission and anisotropic rotation\u0000of the probe polarization plane. These effects are described microscopically in\u0000a toy model and their symmetry analysis is presented. Both are observed\u0000experimentally on the D2 resonance of cesium vapor and agree with the\u0000theoretical predictions. The large magnitude of the quadrupole dichroism makes\u0000it promising for magnetometric applications and for studying the effects of\u0000anisotropic bleaching.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preventing overfitting in infrared ellipsometry using temperature dependence: fused silica as a case study","authors":"Shenwei Yin, Jin-Woo Cho, Demeng Feng, Hongyan Mei, Tanuj Kumar, Chenghao Wan, Yeonghoon Jin, Minjeong Kim, Mikhail A. Kats","doi":"arxiv-2409.05323","DOIUrl":"https://doi.org/arxiv-2409.05323","url":null,"abstract":"The dispersive linear optical properties of materials are frequently\u0000described using oscillator models, where the oscillators represent interactions\u0000between light and various material resonances (vibrational, free-carrier,\u0000interband, etc.). The state-of-the-art measurement of the complex refractive\u0000index is variable-angle spectroscopic ellipsometry (VASE), where additional\u0000measurement angles and the measured depolarization of light provides much more\u0000information compared to simpler measurements such as single-angle reflectance\u0000and transmittance. Nevertheless, even state-of-the-art VASE data can be hard to\u0000uniquely fit using oscillator models, and the resulting models may be hard to\u0000interpret physically. Here, we demonstrate the use of an additional degree of\u0000freedom, temperature, to improve the accuracy, uniqueness, and physicality of\u0000oscillator models of materials. Our approach relies on the well-understood\u0000temperature dependence of material resonances, and in particular vibrational\u0000resonances in amorphous SiO2, which are expected to change monotonically from\u0000room temperature to hundreds of degrees C. We performed VASE measurements at\u0000different temperatures, independently fitted the data at each temperature, and\u0000then confirmed that our models are unique and physical by monitoring the\u0000temperature dependence of the resulting fitting parameters. Using this\u0000technique, we generated highly accurate and precise data sets and material\u0000models describing the mid-infrared complex refractive index of three different\u0000grades of fused SiO2, which can then be used for modeling of mid-infrared\u0000optical components such as thermal emitters.","PeriodicalId":501214,"journal":{"name":"arXiv - PHYS - Optics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}