超宽带光参量放大器中相位匹配结构的分析和优化

Analysis and Optimization of Phase-Matching Configuration in Ultrabroadband Optical Parametric Amplifier

对光参量放大的相位匹配进行了研究,建立了产生超宽增益带宽参量放大相位匹配的一般物理模型,依据这一模型,在只给定抽运光波长和晶体参数的条件下,可以确定超宽带相位匹配结构和信号光匹配波长。以偏硼酸钡(BBO)晶体为例进行了模拟计算,结果表明,非共线相位匹配的两种不同结构有着相差极大的晶体接收角。讨论了如何优化非共线相位匹配结构参数以便得到极大增益带宽和极佳晶体接收角的问题。对BBO晶体光参量放大的光谱相位匹配的计算结果可以为多光束抽运或多阶段光参量放大的设计提供理论依据。

The phase-matching configuration of optical parametric amplification （OPA） is investigated. The general physical model for evaluating the phase-matching scheme capable of generating ultra-broad gain bandwidth is developed. Based on this model, the phase-matching configuration and the corresponding matching signal wavelength can be obtained only under the conditions of a given pump wavelength and nonlinear crystal parameters. Numerical simulations, taking β-BaB2O4 （BBO） crystal for example, are performed, and the results show that there is a extreme difference for the acceptance angles between two different non-collinear phase-matching configurations. Analysis and optimization of non-collinear phase matching parameters are also carried out in order to obtain maximum gain bandwidth and excellent crystal acceptance angle. The calculated results of spectral phase-matching range for OPA based on BBO crystal, can also provide a theoretical basis for the designs of multi-beam-pumped or multi-stage OPA systems.