太赫兹参量源研究进展

Research progress of terahertz parametric sources

太赫兹参量源是一种激光驱动的太赫兹辐射源,它具有高相干性、可调谐、室温运转等优点。在简要介绍太赫兹参量源的基本原理后,重点总结了近年来国内外对太赫兹参量源的代表性研究成果,主要包括:1)太赫兹参量源中常用的几种非线性晶体,包括铌酸锂、磷酸钛氧钾、砷酸钛氧钾、磷酸钛氧铷;2)大单脉冲能量太赫兹参量源,主要产生方法包括使用垂直表面出射结构、使用环形腔、增加非线性晶体损伤阈值等,目前报道的最大单脉冲能量达到17μJ;3)高平均功率太赫兹参量源,主要产生方法包括使用半导体激光器侧面泵浦激光器、兼顾提高泵浦光脉冲能量和脉冲重复频率等,目前报道的最大平均功率为367μW;4)太赫兹参量源的理论模拟,主要包括以耦合波方程为基础的,分别针对太赫兹参量产生器、种子注入式太赫兹参量产生器、内腔泵浦与外腔泵浦太赫兹参量振荡器建立的理论模型。

Terahertz parametric source is a laser driven terahertz wave radiation source,which has many advantages such as high coherence,wide tunability and room temperature operation,etc.After a brief introduction to basic principle of terahertz parametric sources,this paper mainly summarizes the recent representative research results about terahertz parametric sources,including:1)Commonly used nonlinear crystals including lithium niobate,potassium titanium phosphate,potassium titanyl arsenate,rubidium titanium phosphate;2)Large pulse energy terahertz parametric sources.The main generation methods include using surface-emitted structure,using ring cavity,increasing the damage threshold of the nonlinear crystal,etc.The largest reported terahertz energy reaches 17µJ;3)High average power terahertz parametric sources.The main generation methods include deploying laser diode side-pumped laser as the pumping source,balancing the increase of the pulse energy and pulse repetition rate simultaneously,etc.The highest terahertz average power reported reaches 367µJ till now;4)Theoretical simulation on different kinds of terahertz source structures.Mainly based on the coupled wave equations,the theoretical models for terahertz parametric generator,injection-seeded parametric generator,intracavity-pumped and extracavity-pumped terahertz parametric oscillators are introduced respectively.