具有三级放大结构的铷蒸气激光系统的优化设计

由于半导体激光泵浦碱金属蒸气激光器（DPAL）的饱和增益较大，因此采用主振荡功率放大器（MOPA）结构对其进行定标放大是实现其高功率化的理想选择。基于端面泵浦DPAL-MOPA系统的微观动力学理论模型设计了铷蒸气DPAL的三级放大系统。另外，分别对长度为3、5、7 cm的三种密闭蒸气池在不同温度条件下的增益特性做了详细的计算与分析，最终确定预放大级的密闭蒸气池长度为3 cm，一级主放大级的为5 cm，二级主放大级的为7 cm。基于这种三级MOPA结构可把功率为50 mW的铷蒸气DPAL种子光放大至1 000 W量级。同时，也评估了采用此设计方案时，整个MOPA系统所产生的自发辐射功率和热功率。该研究对将来实现高功率DPAL提供了设计思路和理论依据。

Optimization design of a powe-scaled rubidium laser with a 3-stage amplification configuration

Because of the extremely high saturation gain of a diod-pumped alkali laser (DPAL), the master oscillator powe-amplifier (MOPA) system is an ideal selection to achieve powe-scaling of DPALs. In this report, a theoretical model based on the kinetic algorithm was established for construction of the 3-stage amplification configuration in which the en-pumped structures were adopted. Then the amplification factors at different temperatures were calculated when the cell lengths in the MOPA system are 3, 5, and 7 cm, respectively. According to the simulation results, a 3 c-long vapor cell was employed for the pr-amplification, a 5 c-long vapor cell was chosen for the first mai-amplification, and a 7 cm-long cell was used for the second mai-amplification. With such a designed MOPA system, the output power over 1000W for a 50mW Rb-DPAL seed light can be optained. In addition, the power of fluorescence and generated heat are evaluated for this 3-stage MOPA system. The research could provide some design schemes and theoretical methodology for realization of a powe-scaled DPAL-MOPA system.