基于衍射/反射光束整形系统的高密度泵浦源

利用二元光学元件微型化和对波面进行任意整形的特点,将二元光学衍射器件用于高功率激光二极管阵列光束的快、慢轴准直,并结合空心导管设计一种衍射/反射混合型光束整形系统,用于实现高密度、高均匀性LD泵浦源.应用时域有限差分法(FDTD)的严格矢量分析表明:所设计的二元光学准直器性能优良,准直后光束发散角在误差范围内接近衍射极限,慢轴方向衍射效率为82.21%,快轴方向为75.76%.模拟设计的结果表明:采用这种衍射/反射光束整形技术的高密度泵浦源能获得高功率密度和高均匀性的抽运光束,在空心导管出射端面附近光强起伏RMS<1%,并且在光束的准直性能和系统紧凑性方面优于传统整形方法.

High density pumping sources based on diffractive/reflective beam shaping systems

The binary optics diffractive elements was used to collimate the beam from high power laser diode array by taking advantage of the micromation and the arbitrary phase modulation characteristics of the binary optics elements.A diffractive/reflective hybrid beam shaping system combining binary elements and hollow ducts was designed to realize a high density and high uniformity LD pumping source.The strict vector analysis,with FDTD method,shows that the binary optics collimator has good performance.The beam divergent angle after collimation is close to the diffraction limit within the error range,and the diffraction efficiency is 82.21%on the slow axis direction and 75.76% on the fast axis direction.The simulation result shows that this kind of LD pumping source has high density and high uniformity in the pumping field,and the RMS of intensity fluctuation near the output surface of the hollow ducts is less than 1%.Moreover.this pumping source is advantageous in beam collimation performance and system compactness compared with the traditional design.