高功率钕玻璃激光系统低时间相干光频率转换技术研究进展

Research progress of low-temporal-coherence light frequency conversion technology for high power Nd:glass laser system

摘要: 低时间相干脉冲可有效提高激光与等离子相互作用中参量不稳定性的阈值，但高效频率转换难题是实现其工程应用瓶颈之一。系统分析了高功率激光驱动器已有的各类低时间相干脉冲频率转换技术的特性，并基于数值模拟和实验分析了部分掺氘DKDP晶体用于超辐射光倍频、三倍频的特性与工程应用可行性，结果表明掺氘17%左右DKDP晶体可以提高钕玻璃系统超辐射光的倍频效率，理论转换效率可达到约80%，10%梯度掺氘DKDP晶体则可实现5 THz带宽三倍频输出。

Abstract: Low temporal coherence pulse can effectively increase the threshold of parametric instabilities in the laser and plasma interaction. However, frequency conversion efficiency is one of the bottlenecks in its engineering application. The characteristics of frequency conversion technologies of various low-coherence pulse for the high-power laser drivers are summarized in this paper, and based on numerical simulations and experiments, application feasibility of partial deuterium DKDP crystals for frequency doubling and tripling of super-luminescent light are analyzed in detail. The results show that 17% deuterium DKDP crystals can be used for efficient frequency doubling of super-luminescent light in neodymium glass systems, and the conversion efficiency can reach about 80%. 10% gradient deuterium DKDP crystals can be used for triple frequency of 5 THz bandwidth.