针对光纤的泵浦耦合问题，对由两片非球面透镜组成的接近1∶1光纤间空间耦合器进行了计算和实验验证.利用高斯光束的变化规律对光路进行了分析研究，并根据二极管输出光相干性不好的特点，对非球面透镜进行了光路追迹的模拟计算.研究发现，在泵浦光波长等因素发生变化时，利用椭球面透镜组成的耦合系统较双曲面透镜有更高的稳定性.实验中选用符合计算结果要求的非球面透镜组成耦合装置,利用一台二极管激光器(尾纤输出端面直径约200 μm，N.A.约0.2)泵浦一段芯径约200 μm(N.A.约0.42)的多模光纤，耦合装置的透过率约95%，在光纤端面有反射的条件下约90%的泵浦光耦合进光纤.

For the aim of the fiber pump coupling, calculation and experiment are carried out for the fiber 1∶1 spatial coupler composed of two aspherical lens. Optical pathway is analyzed according to the variation regularity of Gaussian beam. According to the poor coherence of the LD output beam, ray tracing calculation is carried out for the optical pathway diagrams of the coupler. It can be found that the coupler constituted with ellipsoid lens is more stable than that with hyperboloid lens in the case of the wavelength changing and so on. The aspherical lens that meets the calculation result is chosen to constitute the coupler. The couplers with transmittance of 95% composed for the experiments demonstrated a coefficient of 90% LD coupling into a length of multimode fiber with core diameter of 200 micro-meter without antireflection coating at the end surface.