根据光线追迹原理,研究用于端面抽运的大面阵激光二极管(LD)抽运源的耦合系统设计。结合当前大口径激光二极管阵列常用的空心导管型耦合系统,分别从耦合效率、抽运强度分布、抽运光传输等方面,讨论大口径激光二极管阵列耦合系统的一般设计准则,提出了将激光二极管阵列单元平面排布改为球面排布的办法。针对100 kW激光二极管阵列,将子阵列作球面排布后,仅用一空心导管来汇聚抽运光,这种设计获得了传输性能优良的大区域均匀分布的抽运场,抽运场起伏小于5%,抽运强度大于20 kW/cm2,耦合效率98%,有效抽运区域内效率达90%。

Based on the ray tracing method, the design of coupling system for large aperture laser diode (LD) arrays applied in end-pumped solid state laser was investigated systematically. Combming the current hollow duct coupling system for large aperture LD arrays, we discuss the common rules in designing coupling system for large aperture LD arrays from the coupling efficiency, energy distribution and propagation characteristics. Also, a new way to predigest the elements of coupling system for large aperture LD arrays by arranging small arrays spherically was introduced. For 100kW LD arrays, using only one hollow duct we obtained excellent results with large uniform pump field by arranging small arrays spherically, and the intensity was more than 20 kW/cm2 with fluctuation less than 5％. The total coupling efficiency is 98％, and around 90％ of energy was contained within the effective area of gain media.