光衰减器在解决信道功率平衡、光纤系统指标测量和全光网络的功率匹配等问题上有着不可或缺的作用。文章基于高斯光束传播及衍射场理论分析, 研究了挡光片型可变光衰减器内部光场的分布情况。基于矩形、三角形、圆形3种挡光片, 对挡光片型光衰减器进行了实验研究。通过实验与理论结果的比较, 得到了3种挡光片的位置与衰减量关系曲线, 结果表明, 三角形挡光片光衰减器性能更佳。

Optical attenuator plays an important role in solving the problem of channel power balance, optical fiber system index measurement, and power matching of all optical networks . In this paper, based on the Gaussian beam propagation and diffraction field theory analysis, the distribution of shutter based variable optical attenuator's internal light field is studied. Based on the rectangle, triangle, round three types of shutter, the shutter based optical attenuator is experimentally investigated. The shutter based optical attenuator’s theory results and experimental results are compared. It is shown that the triangle shaped shutter optical attenuator has the best performance.