Leo F, Hansson T, Ricciardi I, De Rosa M, Coen S, Wabnitz S, Erkintalo M
The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, Auckland 1142, New Zealand.
Department of Applied Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden.
Phys Rev Lett. 2016 Jan 22;116(3):033901. doi: 10.1103/PhysRevLett.116.033901. Epub 2016 Jan 21.
We derive a time-domain mean-field equation to model the full temporal and spectral dynamics of light in singly resonant cavity-enhanced second-harmonic generation systems. We show that the temporal walk-off between the fundamental and the second-harmonic fields plays a decisive role under realistic conditions, giving rise to rich, previously unidentified nonlinear behavior. Through linear stability analysis and numerical simulations, we discover a new kind of quadratic modulation instability which leads to the formation of optical frequency combs and associated time-domain dissipative structures. Our numerical simulations show excellent agreement with recent experimental observations of frequency combs in quadratic nonlinear media [Phys. Rev. A 91, 063839 (2015)]. Thus, in addition to unveiling a new, experimentally accessible regime of nonlinear dynamics, our work enables predictive modeling of frequency comb generation in cavity-enhanced second-harmonic generation systems. We expect our findings to have wide impact on the study of temporal and spectral dynamics in a diverse range of dispersive, quadratically nonlinear resonators.
我们推导了一个时域平均场方程，以模拟单共振腔增强二次谐波产生系统中光的完整时间和光谱动力学。我们表明，在实际条件下，基频场和二次谐波场之间的时间走离起着决定性作用，从而产生了丰富的、以前未被识别的非线性行为。通过线性稳定性分析和数值模拟，我们发现了一种新型的二次调制不稳定性，它导致了光学频率梳和相关时域耗散结构的形成。我们的数值模拟与最近在二次非线性介质中对频率梳的实验观测结果 [《物理评论A》91, 063839 (2015)] 显示出极好的一致性。因此，除了揭示一种新的、可通过实验获取的非线性动力学机制外，我们的工作还能够对腔增强二次谐波产生系统中的频率梳产生进行预测建模。我们预计我们的发现将对各种色散、二次非线性谐振器中的时间和光谱动力学研究产生广泛影响。
