基于振动弛豫理论提高光抽运太赫兹激光器输出功率的研究

Improvement of the output power of optical pumping THz lasers based on the theory of vibrational relaxation

以半经典密度矩阵理论和分子振动弛豫理论为基础,研究添加适当比例缓冲气体与适当减小波导芯径对光抽运太赫兹激光器输出光强的影响.计算结果表明,加入适当比例缓冲气体或适当减小波导的芯径均能提高太赫兹激光的输出光强;同时优化两个参数能进一步提高抽运激光能量转化为太赫兹激光能量的效率,延长工作腔中的有效激活区,延缓抽运饱和效应的出现,提高太赫兹激光输出光强.该研究对提高光抽运太赫兹激光器的能量转化效率、提高光抽运太赫兹激光器的输出功率及实现光抽运太赫兹激光器的小型化有重要的指导意义.

Based on the semiclassical density matrix theory and vibrational relaxation theory,the present paper studies the infuences on optical pumping THz lasers output power due to adding an appropriate proportion of bufer gas and appropriately reducing the waveguide core diameter.Results prove that adding appropriate proportion of bufer gas or appropriately reducing the waveguide core diameter can increase the output of light intensity of THz laser.Optimizing the two parameters at the same time can further improve the efciency of pumping laser energy into THz laser energy,extend the efective activation area of the working cavity,put of the appearance of the pumping saturation efect,and increase the output power of the THz lasers.This research may have a guiding signifcance for the THz optical pumping laser in improving energy conversion efciency,and increasing the output power so as to bring about the miniaturization of THz optical pumping laser.