利用正弦光栅探测激光信息的理论研究

Theoretical study of detect laser information by sinusoidal grating

利用傅里叶变换理论研究了激光以任意角度入射正弦光栅的夫琅和费衍射,并对衍射图像的相对光强分布进行了分析,得到了零级和正负一级明纹中心位置与入射激光信息之间的关系以及对应的明纹宽度。通过数据处理,反向推导出了入射激光的波长和方向与明纹位置的关系,进而获得了计算入射激光参数的方法。根据计算结果提出了采用CCD观测衍射图像、利用DSP高速采集信号和单片机处理数据的样机设计方案。在对样机各类参数进行了论证的基础上,推算了样机性能。

In this paper,Fraunhofer diffraction of sinusoidal grating aroused by random incidence laser is studied.Distribution of relative light intensity is analyzed.Relationship between bright stripe′s location and incidence laser′s information is studied and width of the bright stripe is also discussed.Formulas are deduced to find out the incoming laser′s wavelength and direction by inputting the location of the bright stripes.Based on the theoretical analysis,design of a prototype device is put forward.The scheme uses a CCD to observe the diffraction pattern,a DSP to sample the transfer the image information and a SCM to process the data.The performances of the prototype are given out with the parameters of the components and units.