现有光栅衍射型激光告警中, 正弦光栅存在±1级衍射效率较低, 闪耀光栅在闪耀波长附近0级和-1级衍射效率很低, 这两种光栅的缺点都降低了激光告警的可靠性。为此文中提出了一种改进型闪耀光栅。将两闪耀光栅反相对接, 并且中间留一定无光栅空间, 此改进可提高波长在闪耀波长附近0级和-1级的衍射效率,将有效克服传统闪耀光栅的漏报警现象。设计加工了闪耀波长为800 nm的改进型闪耀光栅, 理论分析了0级和±1级衍射效率; 采用波长为808 nm和850 nm的光, 对改进型闪耀光栅进行二维激光告警实验测试, 实验结果表明, 在波长为闪耀波长附近光入射时, 改进型较普通闪耀光栅的0级和-1级衍射强度有很大提高, 能够被CCD有效探测。该改进型闪耀光栅可有效提高二维激光告警系统的可靠性。

Existing laser warning based on the diffraction grating has the following disadvantages. The diffraction efficiencies of ±1 order based on sinusoidal grating are low and the diffraction efficiencies of -1 order and 0 order based on blazed grating are very low. These shortcomings have reduced the reliability of the laser warning. A method for improving the blazed grating was presented. The two blazed gratings inverted docking, some no grating space was vacated in the middle of the grating. This improvement can increase the diffraction efficiencies of -1 order and 0 order. This grating will effectively overcome the missing alarm. The improved blazed grating was designed and processed with blazed wavelength λ=800 nm. The diffraction efficiencies of 0 order and ±1 order were derived. This grating was tested by two-dimensional laser warning using the laser with λ=808 nm and λ=850 nm. When wavelength of the incident light close to the blaze wavelength, the experimental results show that the improved blazed grating diffraction efficiencies of -1 order and 0 order have greatly improved, and they can be effectively detected by CCD. The reliability of two-dimensional laser warning is improved using this improved blazed grating.