为了满足常温Yb: YAG激光放大器对泵浦功率密度的要求，设计了一种高缩束比的耦合系统。根据激光二极管(LD)的发光特性，将输出功率为80 kW的LD阵列进行拟球面排列，采用正交柱面透镜配合空心导光管进行泵浦耦合，耦合系统的面积缩束比高达86∶1。模拟计算表明，该耦合系统的耦合效率对导光管反射板的反射率依赖性较低，且脱离耦合系统后的泵浦光传输8.5 mm后，依然可以保持泵浦光场的轮廓,满足端面泵浦的常温Yb: YAG片状放大器对泵浦耦合系统的要求。

In order to meet the pump power density requirements of room-temperature Yb: YAG laser amplifier, a coupling system of high contraction coefficient has been designed. Laser diode (LD) arrays of 80 kW output power are arranged to be spherical. Orthogonal cylindrical lenses and a hollow duct are used for pump-coupling according to luminescence properties of LD. The contraction coefficient is up to 86∶1. Simulations show that the coupling efficiency of the coupling system depends weakly on the reflectivity of the reflectors of the hollow duct. The pump light can transport over a distance of at least 8.5 mm with its shape maintained. The coupling system can meet the requirements of the end-pumped room-temperature Yb: YAG slab amplifier.