Solitons are self-reinforcing localized wave packets that manifest in the major areas of nonlinear science,from optics to biology and Bose-Einstein condensates.Recently,optically driven dissipative solitons have attra...Solitons are self-reinforcing localized wave packets that manifest in the major areas of nonlinear science,from optics to biology and Bose-Einstein condensates.Recently,optically driven dissipative solitons have attracted great attention for the implementation of the chip-scale frequency combs that are decisive for communications,spectroscopy,neural computing,and quantum information processing.In the current understanding,the generation of temporal solitons involves the chromatic dispersion as a key enabling physical effect,acting either globally or locally on the cavity dynamics in a decisive way.Here,we report on a novel class of solitons,both theoretically and experimentally,which builds up in spectrally confined optical cavities when dispersion is practically absent,both globally and locally.Precisely,the interplay between the Kerr nonlinearity and spectral filtering results in an infiinite hierarchy of eigenfunctions which,combined with optical gain,allow for the generation of stable dispersion-less dissipative solitons in a previously unexplored regime.When the filter order tends to infinity,we find an unexpected link between dissipative and conservative solitons,in the form of Nyquist-pulse-like solitons endowed with an ultra-flat spectrum.In contrast to the conventional dispersion-enabled nonlinear Schr?dinger solitons,these dispersion-less Nyquist solitons build on a fully confined spectrum and their energy scaling is not constrained by the pulse duration.Dispersion-less soliton molecules and their deterministic transitioning to single solitons are also evidenced.These findings broaden the fundamental scope of the dissipative soliton paradigm and open new avenues for generating soliton pulses and frequency combs endowed with unprecedented temporal and spectral features.展开更多
We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and ...We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and avoids the cutoff of the higher-order modes, which is a common problem in elliptical core polarization-maintaining few-mode fibers. Using a high-contrast index ring and stress-induced birefringence, the PM-PRCF features support for 10 vector modes, with effective refractive index separations from their adjacent modes >10^(-4).Broadband performance is investigated subsequently over a wide wavelength range from 1500 to 1630 nm.The proposed fiber is targeted at applications in space-division multiplexing while eliminating the complex multiple-input multiple-output signal processing.展开更多
Microcomb generation with simultaneous χ2 and χ3 nonlinearities brings new possibilities for ultrabroadband and potentially self-referenced integrated comb sources. However, the evolution of the intracavity field in...Microcomb generation with simultaneous χ2 and χ3 nonlinearities brings new possibilities for ultrabroadband and potentially self-referenced integrated comb sources. However, the evolution of the intracavity field involving multiple nonlinear processes shows complex dynamics that are still poorly understood. Here, we report on strong soliton regulation induced by fundamental–second-harmonic(FD-SH) mode coupling. The formation of solitons from chaos is extensively investigated based on coupled Lugiato–Lefever equations. The soliton generation shows more deterministic behaviors in the presence of FD-SH mode interaction, which is in sharp contrast with the usual cases where the soliton number and relative locations are stochastic. Deterministic single soliton transition, soliton binding, and prohibition are observed, depending on the phase-matching condition and coupling coefficient between the fundamental and second-harmonic waves. Our finding provides important new insights into the soliton dynamics in microcavities with simultaneous χ~2and χ~3nonlinearities and can be immediate guidance for broadband soliton comb generation with such platforms.展开更多
This paper presents an introduction to the researches in microwave photonics based packages and its application, a 973 project (No. 2012CB315600), which focuses on addressing new requirements for millimeter wave (...This paper presents an introduction to the researches in microwave photonics based packages and its application, a 973 project (No. 2012CB315600), which focuses on addressing new requirements for millimeter wave (MMW) system to work with higher frequency, wider bandwidth, larger dynamic range and longer distance of signal distribution. Its key scientific problems, main research contents and objectives are briefed, and some latest achievements by the project team, including generation of linear frequency modulation wave (LFMW), tunable optoelectronic oscillator (OEO) with lower phase noise, reconfigurable filter with higher Q value, time delay line with wider frequency range, down conversion with gain, and local oscillator (LO) transmission with stable phase, are introduced briefly.展开更多
基金supported by the National Key R&D Program of China under grant no.2018YFA0701902the National Natural Science Foundation of China under grant no.61690192+1 种基金Zhejiang Lab under grant no.2020LC0AD01.P.G.acknowledges support from the EiPhi Graduate School under grant no.ANR-17-EURE-0004the French ISITE-BFC programs under grant no.ANR-15-IDEX-0003.
文摘Solitons are self-reinforcing localized wave packets that manifest in the major areas of nonlinear science,from optics to biology and Bose-Einstein condensates.Recently,optically driven dissipative solitons have attracted great attention for the implementation of the chip-scale frequency combs that are decisive for communications,spectroscopy,neural computing,and quantum information processing.In the current understanding,the generation of temporal solitons involves the chromatic dispersion as a key enabling physical effect,acting either globally or locally on the cavity dynamics in a decisive way.Here,we report on a novel class of solitons,both theoretically and experimentally,which builds up in spectrally confined optical cavities when dispersion is practically absent,both globally and locally.Precisely,the interplay between the Kerr nonlinearity and spectral filtering results in an infiinite hierarchy of eigenfunctions which,combined with optical gain,allow for the generation of stable dispersion-less dissipative solitons in a previously unexplored regime.When the filter order tends to infinity,we find an unexpected link between dissipative and conservative solitons,in the form of Nyquist-pulse-like solitons endowed with an ultra-flat spectrum.In contrast to the conventional dispersion-enabled nonlinear Schr?dinger solitons,these dispersion-less Nyquist solitons build on a fully confined spectrum and their energy scaling is not constrained by the pulse duration.Dispersion-less soliton molecules and their deterministic transitioning to single solitons are also evidenced.These findings broaden the fundamental scope of the dissipative soliton paradigm and open new avenues for generating soliton pulses and frequency combs endowed with unprecedented temporal and spectral features.
基金973 Program(2014CB340003)National Natural Science Foundation of China(NSFC)(61307081,61321004,61420106003)
文摘We present a polarization-maintaining PANDA ring-core fiber(PM-PRCF) characterized by the combination of a ring-core structure with two stress-applying rods. This special fiber design separates the adjacent modes and avoids the cutoff of the higher-order modes, which is a common problem in elliptical core polarization-maintaining few-mode fibers. Using a high-contrast index ring and stress-induced birefringence, the PM-PRCF features support for 10 vector modes, with effective refractive index separations from their adjacent modes >10^(-4).Broadband performance is investigated subsequently over a wide wavelength range from 1500 to 1630 nm.The proposed fiber is targeted at applications in space-division multiplexing while eliminating the complex multiple-input multiple-output signal processing.
基金National Natural Science Foundation of China(NSFC)(61420106003,61690191,61690192)Natural Science Foundation of Beijing Municipality(4172029)
文摘Microcomb generation with simultaneous χ2 and χ3 nonlinearities brings new possibilities for ultrabroadband and potentially self-referenced integrated comb sources. However, the evolution of the intracavity field involving multiple nonlinear processes shows complex dynamics that are still poorly understood. Here, we report on strong soliton regulation induced by fundamental–second-harmonic(FD-SH) mode coupling. The formation of solitons from chaos is extensively investigated based on coupled Lugiato–Lefever equations. The soliton generation shows more deterministic behaviors in the presence of FD-SH mode interaction, which is in sharp contrast with the usual cases where the soliton number and relative locations are stochastic. Deterministic single soliton transition, soliton binding, and prohibition are observed, depending on the phase-matching condition and coupling coefficient between the fundamental and second-harmonic waves. Our finding provides important new insights into the soliton dynamics in microcavities with simultaneous χ~2and χ~3nonlinearities and can be immediate guidance for broadband soliton comb generation with such platforms.
文摘This paper presents an introduction to the researches in microwave photonics based packages and its application, a 973 project (No. 2012CB315600), which focuses on addressing new requirements for millimeter wave (MMW) system to work with higher frequency, wider bandwidth, larger dynamic range and longer distance of signal distribution. Its key scientific problems, main research contents and objectives are briefed, and some latest achievements by the project team, including generation of linear frequency modulation wave (LFMW), tunable optoelectronic oscillator (OEO) with lower phase noise, reconfigurable filter with higher Q value, time delay line with wider frequency range, down conversion with gain, and local oscillator (LO) transmission with stable phase, are introduced briefly.