基于偏振分光互注入锁相的量子级联激光器相干合成技术研究

Mid-infrared lasers with high power and good beam quality have brilliant prospect in environmental monitoring, optical communication and directed infrared countermeasure. The output power of single QCLcannot meet the requirement, so coherent beam combining paves an effective way to obtain high power operation for multiple QCLs. In order to solve the issues of low power, less emitters and poor scaling in current coherent beam combining systems of QCLs, this research will propose an innovative approach to achieve efficient coherent beam combining of QCLs by mutual injection phase-lockingbased on polarization beam splitter. Firstly, the theoretical model of mutual injection phase-locked QCLs will be investigated, which makes clear the impact factors on phase-locking bandwidth and stability region. Secondly, the properties of mutual injection of two QCLs will be studied by experiment. To obtain stable and efficient phase-locking operation, the coupling ratio should be optimized according to the mutual injection theory. Finally, exploring the mechanism of mutual injection phase-locking process with multiple QCLs is essential for coherent beam combining of QCLs to perform a technology solution with high power, good beam quality and power scaling. This research will eventually provide reliable high power mid-infrared laser sources for optical communication and electro-optical countermeasure.

高功率和高光束质量的中红外激光在环境监测、空间通讯和光电对抗等领域有重要的应用前景。单个量子级联激光器的输出功率往往不能满足应用需求，因此需要通过相干合成来获得高功率的中红外激光。本项目针对目前量子级联激光器相干合成中面临的输出功率低、合成路数少和扩展性差等问题，拟对基于偏振分光互注入锁相的量子级联激光器相干合成技术进行研究。主要研究内容包括：（1）通过建立量子级联激光器互注入耦合理论模型，明确影响锁定频率带宽和锁定状态的因素；（2）研究2路量子级联激光器互注入特性，依据理论计算优化耦合系数，并实现稳定、高效的锁相输出；（3）探索多路互注入锁相中的机制，形成高功率、高光束质量、扩展性强的中红外激光相干合成技术方案。以上研究结果将为空间通讯和光电对抗领域提供可靠的高功率中红外光源。

高功率和高光束质量的中红外激光在环境监测、空间通讯和光电对抗等领域有重要的应用前景。光束相干合成是实现高功率和高光束质量输出的有效途径。本项目针对目前量子级联激光器相干合成中面临的输出功率低、合成路数少和扩展性差等问题，对基于偏振分光互注入锁相的量子级联激光器相干合成技术进行研究。本项目建立了量子级联激光器互注入锁相的理论模型，认识了互注入锁相中的动力学过程，明确了相位锁定状态下耦合系数对频率失谐的影响；实验上验证了2路和3路量子级联激光器的互注入锁相相干合成技术；形成了路数多、功率扩展性强的中红外量子级联激光器相干合成技术方案，为高功率、高光束质量的中红外激光相干合成奠定基础，成为红外对抗领域所需的高功率优质光源的解决途径之一。总之，本项目基本完成了申请书中的研究内容，没有进行大的调整，实现了项目的研究目标。发表正式SCI期刊论文1篇，授权专利2项。