Soliton formation in a femtosecond optical parametric pumped by the second harmonic of a Yb: KGW solid-state oscillator was investigated. The intracavity group delay dispersion was positive, and the soliton condition was satisfied by introducing negative nonlinearity from cascaded quadratic nonlinearity (CQN). Controllable CQN was induced by an additional second-harmonic-generating nonlinear crystal inside the same resonator. Close to zero-phase mismatch, high CQN allows higher-order soliton formation, which leads to output power increase, self-phase modulation phase-matched dispersive wave formation, pulse splitting under perturbations of higher orders of nonlinear phase, and stable time/spectral domain oscillations with soliton period. Numerical simulations were employed to aid interpretations of the experimental data.

中文翻译：

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具有正群时延色散的飞秒光学参量振荡器中的受控孤子形成

研究了由Yb：KGW固态振荡器的二次谐波激发的飞秒光学参量中的孤子形成。腔内群时延色散为正，通过级联二次非线性（CQN）引入负非线性来满足孤子条件。可控的CQN是由同一谐振器内部另外一个产生二次谐波的非线性晶体引起的。接近零相位失配，高CQN允许形成高阶孤子，从而导致输出功率增加，自相位调制相位匹配色散波形成，在高阶非线性相位扰动下的脉冲分裂以及稳定的时间/频谱孤子周期的磁畴振荡。数值模拟被用来帮助解释实验数据。