摘要
衍射光学元件被广泛应用于激光光束整形领域中。然而,在实际测量中常常发现衍射效率实际的测量值与设计值存在较大的偏差,原因之一在于输出的焦斑主瓣以外会产生高级次衍射杂散光。文中从理论上推导了高级次衍射杂散光产生的原因并对具有不同设计参数的衍射光学元件进行了仿真分析。通过研究,定义了一个新的参数,相对周期。它与光波波长成正比,与衍射光学元件的采样单元尺寸以及远场衍射角成反比。结果表明,衍射光学元件的衍射效率只是关于相对周期的函数,而与焦斑主瓣的具体形状无关。随着相对周期的增加,衍射效率随之增大。所以可通过适当选取远场衍射角和采样单元尺寸的参数以调整相对周期的大小,有效抑制高级次衍射杂散光。该参数在衍射元件的设计中具有重要的指导意义。
Diffractive optical elements （DOEs） have been widely applied to acquire different beam shapes in illumination systems. However, the experimental values of diffraction efficiency are greatly different from the ideal values because of stray light of high diffractive orders around the targeted spot. The reasons were theoretically discussed for the stray light and many DOEs with different design parameters were simulated. Through the simulation analysis, a new parameter, named relative period, was defined. It was proportional to the wavelength and inversely proportional to the far-field diffraction angle and the size of DOE cells. It is suggested that the diffraction efficiency, which is independent from the beam shapes, could be improved by increasing relative period. As a result, the stray light of high diffractive orders could be suppressed effectively by regulating the parameters of the far-field diffraction angle and the size of DOE cells. The new parameter has an important role in the design of DOE.
出处
《红外与激光工程》
EI
CSCD
北大核心
2013年第11期3059-3064,共6页
Infrared and Laser Engineering
关键词
衍射光学元件
光束整形
衍射效率
相对周期
diffractive optical elements
beam shaping
dffraction efficiency
relative period
作者简介
殷可为（1986-），男，博士生，主要从事应用于光束整形的衍射光学器件方面的研究。Email：ykw．258@163．com
导师简介：邢廷文（1965-），男，研究员，博士生导师，主要从事应用光学方面的研究工作。Email：xingtw@ioe．ac．cn
