角抽运优化及辐射平衡激光器增益介质设计

角抽运能够避免使用抽运光高透激光高反的双色镜,并且对于低掺杂浓度的激光晶体仍然具有可以接受的吸收效率,因此该抽运方案适合辐射平衡激光器(RBL)较为苛刻的抽运要求.为确保抽运光不会从增益介质的角边泄漏,对角抽运方案中的晶体宽度给出了进一步的优化公式.在992.8 nm抽运光波长下,针对用于辐射平衡激光器的掺杂原子数分数为5%的Yb:KGW激光晶体,利用光线追迹法分别对不使用和使用高温熔合技术的两种角抽运设计方案进行了数值模拟计算.根据抽运吸收效率和均匀性等设计要求,两种角抽运方案中最佳入射角度均为45°,最佳抽运全反射次数值均为1,但是使用高温熔合技术比不使用该技术会使抽运效率提高约20%.

Corner-Pumped Configuration Optimization and the Gain Medium Design of Radiation-Balanced Laser

In corner-pumped configuration, dichroic mirror of high transparency for pump light and high reflection for laser light can be avoided, and with laser crystal of low doping concentration the pump absorption efficiency is still acceptable, so this pump configuration is suitable for demanding pumping requirements of radiation-balanced laser (RBL). The formula for the laser crystal width is optimized in corner-pumped configuration to avoid the leakage of the pump light from the crystal pumping corner. When the pumping wavelength is 992.8 nm and the laser crystal of RBL is Yb:KGW with 5% doping concentration, ray trace method is applied to simulate corner-pumped configurations both with and without diffusion technique numerically. According to efficiency and uniformity of pumping light absorption, in the design of both configurations the best pump incident angle is 45° and the best pump total reflection number is 1, but the corner-pumped configuration with diffusion technique is about 20% more efficient than the that without it.