Observation of a gradient catastrophe generating solitons

Generating octave-bandwidth soliton frequency combs with compact, low-power semiconductor lasers

We report a comprehensive study of low-power, octave-bandwidth, single-soliton microresonator frequency combs in both the 1550 nm and 1064 nm bands. Our experiments utilize fully integrated silicon-nitride Kerr microresonators, and we demonstrate direct soliton generation with widely available distributed-Bragg-reflector lasers that provide less than 40 mW of chip-coupled laser power. We report measurements of soliton thermal dynamics and demonstrate how rapid laser-frequency control, consistent with the thermal timescale of a microresonator, facilitates stabilization of octave-bandwidth solit…

Fast Inverse Nonlinear Fourier Transform For Generating Multi-Solitons In Optical Fiber

The achievable data rates of current fiber-optic wavelength-division-multiplexing (WDM) systems are limited by nonlinear interactions between different subchannels. Recently, it was thus proposed to replace the conventional Fourier transform in WDM systems with an appropriately defined nonlinear Fourier transform (NFT). The computational complexity of NFTs is a topic of current research. In this paper, a fast inverse NFT algorithm for the important special case of multi-solitonic signals is presented. The algorithm requires only $\mathcal{O}(D\log^{2}D)$ floating point operations to compute $D…

Generating mid-IR octave-spanning supercontinua and few-cycle pulses with solitons in phase-mismatched quadratic nonlinear crystals

We discuss a novel method for generating octave-spanning supercontinua and few-cycle pulses in the important mid-IR wavelength range. The technique relies on strongly phase-mismatched cascaded second-harmonic generation (SHG) in mid-IR nonlinear frequency conversion crystals. Importantly we here investigate the so-called noncritical SHG case, where no phase matching can be achieved but as a compensation the largest quadratic nonlinearities are exploited. A self-defocusing temporal soliton can be excited if the cascading nonlinearity is larger than the competing material self-focusing nonlinear…

新型被动锁模光纤激光器中周期性光谱和孤子分子的观测

Observation of periodic optical spectra and soliton molecules in a novel passively mode-locked fiber laser

提出一种利用非线性放大环形镜锁模的全保偏掺铒光纤激光器，无需额外调整即可稳定输出孤子分子，首次观测到具有两个完整周期的周期性光谱，并建立多稳态模型解释该现象。

Numerical realization of the variational method for generating self-trapped beams

We introduce a numerical variational method based on the Rayleigh-Ritz optimization principle for predicting two-dimensional self-trapped beams in nonlinear media. This technique overcomes the limitation of the traditional variational approximation in performing analytical Lagrangian integration and differentiation. Approximate soliton solutions of a generalized nonlinear Schrödinger equation are obtained, demonstrating robustness of the beams of various types (fundamental, vortices, multipoles, azimuthons) in the course of their propagation. The algorithm offers possibilities to produce more …

Vortical light bullets in second-harmonic-generating media supported by a trapping potential

We introduce a three-dimensional (3D) model of optical media with the quadratic ($χ^{(2)}$) nonlinearity and an effective 2D isotropic harmonic-oscillator (HO) potential. While it is well known that 3D χ^2 solitons with embedded vorticity ("vortical light bullets") are unstable in the free space, we demonstrate that they have a broad stability region in the present model, being supported by the HO potential against the splitting instability. The shape of the vortical solitons may be accurately predicted by the variational approximation (VA). They exist above a threshold value of the total ener…

在\(χ^{(2)}+χ^{(3)}\)微谐振器中通过参量下转换实现的多孤子态

Multiple soliton regimes enabled by parametric down-conversion in $χ^{(2)}+χ^{(3)}$ microresonators

研究\(χ^{(2)}+χ^{(3)}\)微谐振器中孤子态，通过数值模拟发现在不同条件下可形成多种孤子，如亮、拓扑双色及暗孤子，展示了\(\chi^{(2)}\)和\(\chi^{(3)}\)非线性相互作用能扩展孤子态范围和类型。

受激拉曼散射对 silica 微腔中暗孤子产生的影响

Impact of Stimulated Raman Scattering on Dark Soliton Generation in a Silica Microresonator

本文研究了 silica 微腔中受激拉曼散射对暗孤子产生的影响，通过分析参量增益与拉曼增益并基于 Lugiato-Lefever 方程数值模拟，发现激发暗孤子需适当的模式耦合和泵浦功率范围。

Energetic mid-IR femtosecond pulse generation by self-defocusing soliton-induced dispersive waves in a bulk quadratic nonlinear crystal

Generating energetic femtosecond mid-IR pulses is crucial for ultrafast spectroscopy, and currently relies on parametric processes that, while efficient, are also complex. Here we experimentally show a simple alternative that uses a single pump wavelength without any pump synchronization and without critical phase-matching requirements. Pumping a bulk quadratic nonlinear crystal (unpoled LiNbO$_3$ cut for noncritical phase-mismatched interaction) with sub-mJ near-IR 50-fs pulses, tunable and broadband ($\sim 1,000$ cm$^{-1}$) mid-IR pulses around $3.0~μ\rm m$ are generated with excellent spati…

耦合非线性薛定谔方程中的畴壁与矢量孤子

Domain Walls and Vector Solitons in the Coupled Nonlinear Schrodinger Equation

本文概述了1D两组分CNLS方程中畴壁和矢量孤子的分类程序，通过将方程简化为实ODE，识别了多种畴壁和生成矢量孤子的余维1机制，并利用数值延拓方法揭示了孤子间的关联及碰撞特征。