We show that, in general, any complex weakly nonlinear highly multimode system can reach thermodynamic equilibrium that is characterized by a unique temperature and chemical potential. The conditions leading to either positive or negative temperatures are explicitly obtained in terms of the linear spectrum of the system, the input power, and the corresponding Hamiltonian invariant. Pertinent examples illustrating these results are provided in various scenarios.
The quest for ever higher information capacities has brought about a renaissance in multimode optical waveguide systems. This resurgence of interest has recently initiated a flurry of activities in nonlinear multimode fiber optics. The sheer complexity emerging from the presence of a multitude of nonlinearly interacting modes has led not only to new opportunities in observing a host of novel optical effects that are otherwise impossible in single-mode settings, but also to new theoretical challenges in understanding their collective dynamics. In this Article, we present a consistent thermodyna…
The complex nonlinear behaviors of heavily multimode lightwave structures have been recently the focus of considerable attention. Here we develop an optical thermodynamic approach capable of describing the thermalization dynamics in large scale nonlinear photonic chain networks - a problem that has remained unresolved so far. A Sackur-Tetrode equation is obtained that explicitly provides the entropy of these systems in terms of all the extensive variables involved. This entropic description leads to a self-consistent set of equations of state from where the optical temperature and chemical pot…
Optical forces are known to arise in a universal fashion in many and diverse physical settings. As such, they are successfully employed over a wide range of applications in areas like biophotonics, optomechanics and integrated optics. While inter-elemental optical forces in few-mode photonic networks have been so far systematically analyzed, little is known, if any, as to how they manifest themselves in highly multimoded optical environments. In this work, by means of statistical mechanics, we formally address this open problem in optically thermalized weakly nonlinear heavily multimode tight-…
We demonstrate experimentally all-optical beam steering in modulated photonic lattices induced optically by three beam interference in a biased photorefractive crystal. We identify and characterize the key physical parameters governing the beam steering, and show that the spatial resolution can be enhanced by the additional effect of nonlinear beam self-localization.
We study the statistical behavior of multimoded optical systems under equilibrium conditions. We investigate the role of variations of the system parameters in the thermodynamic description and derive, an optical analogue of the first law of thermodynamics, a generic expression for the work done to the system, and an optical Gibbs-Duhem equation. To demonstrate these effects, we focus in the case of two-dimensional photonic lattices. We study the conditions under which the entropy in such waveguide arrays can be considered as extensive. In this respect, small deviations from the extensive char…
Wavelength-Dependent Evolution of Full-Field Transfer Matrices in Photonic Lanterns
College of Optics and Photonics (CREOL), University of Central Florida（中央佛罗里达大学光学与光子学院（CREOL））；University of Sydney（悉尼大学）；Department of Physics — Planetary Sciences, University of Central Florida（中央佛罗里达大学行星科学物理系）；Florida Space Institute, University of Central Florida（中央佛罗里达大学佛罗里达太空研究所）
The coherent photogalvanic effect leads to the generation of a current under the absorption interference of coherent beams and allows for the inscription of space-charge gratings leading to an effective second-order susceptibility ($χ^{(2)}$). The inscribed grating automatically results in quasi-phase-matching between the interfering beams. Theoretical and experimental studies have been carried out, mostly focusing on the degenerate case of second-harmonic generation, showing significant conversion efficiency enhancements. However, the link between the theory and experiment was not fully estab…
Frequency combs and coherent dissipative structures in nonlinear optical microresonators
Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；Universität Hamburg（汉堡大学）；Laboratoire Temps-Fréquence, Université de Neuchâtel（纳沙泰尔大学时间频率实验室）；Swiss Federal Institute of Technology (EPFL)（瑞士联邦理工学院（洛桑联邦理工学院））
Unique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and,…
Continuous-wave pumped optical microresonators have been vastly exploited to generate frequency comb (FC) utilizing the Kerr nonlinearity. Most of the nonlinear materials used to build photonic platforms exhibit nonlinear losses such as multi-photon absorption, free-carrier absorption (FCA), and free-carrier dispersion (FCD) which can strongly affect the nonlinear characteristics of the devices made out of these materials. In this work, we model the Kerr FC based on modified Lugiato-Lefever Equation (LLE) along with the rate equation and develop analytical formulations to make quick estimation…
Brillouin Scattering Selection Rules in Polarization-Sensitive Photonic Resonators
Université Paris-Saclay（巴黎萨克雷大学）；CNRS, Centre de Nanosciences et de Nanotechnologies（法国国家科学研究中心，纳米科学中心）；Quandela SAS（Quandela公司）；Université Paris-Cité（巴黎西岱大学）；Institute of Physics, Carl von Ossietzky University（卡尔·冯·奥西茨基大学物理研究所）
In this Review, the theory and applications of optical micro and nanoresonators are presented from the underlying concept of their natural resonances, the so-called quasi-normal modes (QNMs). The latter are the basic constituents governing the response of resonators. Characterized by complex frequencies, QNMs are initially loaded by a driving field and then decay exponentially in time due to power leakage or absorption. Here, the use of QNM-expansion formalisms to model these basic effects is explored. Such modal expansions that operate at complex frequencies distinguish from the current user …
In recent years, there has been considerable interest in the study of wave propagation in nonlinear photonic lattices. The interplay between nonlinearity and periodicity has led researchers to manipulate light and discover new and interesting phenomena such as new classes of localized modes, usually referred to as solitons, and novel surface states that propagate robustly. A field where both nonlinearity and periodicity arises naturally is nonlinear optics. But there are other areas where waves propagating on background lattices play an important role, including photonic crystal fibers and Bos…
