数字微镜器件用于光束空间整形

Spatial Laser Beam Shaping Using Digital Micromirror Device

介绍了数字微镜器件(DMD)的工作原理,当DMD某像素微镜的角度固定在+12°或-12°,其在光学上等价于控制该像素的透射率为0或1。结合二元面板的设计思想,用误差扩散法对DMD各像素微镜的状态进行设计,用以对1053 nm脉冲光进行空间整形,实现了一种主动、实时的光脉冲空间整形方案。填充因子(FF)和光场调制度(FM)作为评价光束近场质量的参数,在高功率激光系统中直接影响系统的能量利用率。上述实验中,经过空间整形,光束的填充因子由33%提高为65%,光场调制度由52%降为28%,而且整形后的光斑大小与预期相符。最后对实验所用的DMD进行了能量利用率、波前畸变稳定性的测试。

The operating principle of digital micromirror device （DMD） is introduced. When the titled angle of a pixel mirror is set at ＋ 12°or -12°, it means that the optical transmissivity of this pixel is 0 or 1. With the help of the design method in binary panels, error diffusion method is used to spatially shape the 1053 nm laser pulse, which also realizes an initiative way of spatial modulation for laser pulse. Filling factor （FF） and field modulation （FM） are both factors which decide the quality of the near field laser beam and they directly affect energy availability factor of the high power laser system. In this experiment, FF increases from 33% to 65% and FM decreases from 52% to 28% after being shaped, and the size of the shaped beam is the same as we expected. At the end, the energy availability factor and mirror stability of this DMD are tested.