高功率中红外PPMgLN-OPO双腔锁定窄线宽光参量技术研究

Mid-infrared laser have important applications in fields such as the military, scientific research and the environment, to achieve high-resolution detection of the physical structure and optoelectronic countermeasures, we need to develop high-power and narrow linewidth mid-infrared optical parametric technology. We design a integrative two-wave coupling dual-cavity, which utilizing the optical parametric process generated signal and idler light, form a narrow linewidth cavity and a amplifier cavity, and achieving high power and narrow linewidth output with high conversion efficiency, which resolve the problem of high threshold by inserting dispersion components and complex laser system by seed injection in the usual narrow linewidth OPO. We will study the mode match, energy conversion process of the OPA, carrying experimental verification of the mid-infrared high power and narrow linewidth parametric oscillator, extending to the hundred watt order with the calibration of two stages OPA. Exploring the oscillator and amplifier process and mechanism of two-wave coupling dual-cavity, building physical model of two-wave coupling dual-cavity and oscillating equation, studying the dynamic and spectral broadening characters, building theoretical model, system design method and analysis soft of hundred watt order high power and narrow linewidth OPO, grasping the laser technology, system parameter design and key technology of the high power and narrow linewidth OPO.

中红外激光在军事、环境和科研等领域有着重要的应用，为了实现对物质结构与特性高分辨率探测和光电对抗，需要发展高功率窄线宽中红外参量技术。本项目提出一体化两波耦合双腔，利用参量过程中的信号光和闲频光，分别形成窄线宽振荡和参量激光放大腔，在高转换效率下实现高光束质量窄线宽的中红外激光输出，解决通常窄线宽光参量振荡器中插入色散元件损耗大、注入种子激光系统复杂等问题。研究参量放大过程模式匹配、能量转移过程，开展高功率窄线宽中红外参量实验验证，利用两级放大对功率放大系统进行定标，推广至百瓦级输出。探索两波耦合腔振荡及参量放大的过程和机理，建立两波耦合双腔激光物理模型和振荡方程，求解方程研究耦合双腔振荡器的动力学特性和光谱特性，建立百瓦级高功率窄线宽光参量理论模型、分析计算软件，以及百瓦级窄线宽中红外激光系统设计方法，掌握高功率窄线宽中红外参量激光技术及系统参数的设计和关键技术。

中红外激光在军事、环境和科研等领域有着重要的应用，为了实现对物质结构与特性高分辨率探测和光电对抗等，需要发展高功率窄线宽中红外激光光源。本项目研究基于PPMgLN晶体的光参量技术，主要内容（1）一体化耦合双腔（OPO）及参量放大器(OPA)结构设计，以实现百瓦量级窄线宽（0.5nm）中红外激光输出的可行性方案；（2）方案振荡级线宽压窄理论研究，放大级放大倍数及线宽展宽理论分析研究；（3）百瓦量级窄线宽中红外激光输出的定标放大方案研究。本研究理论分析了两波耦合双腔的耦合机制，提出了优化方案实现窄线宽中红外激光的高功率输出；理论分析了参量系统振荡级参量光各展宽因素；以及实现窄线宽闲频光的必要条件；实验上利用优化方案，实现了窄线宽1W的闲频光输出，理论分析其线宽约为0.1nm，测量信号光的线宽为0.045nm，验证了理论分析的正确性；同时分析了OPA系统放大倍数与线宽展宽倍数的关系；提出了实现百瓦量级可行性方案。