激光告警中近红外焦平面阵列探测器成像技术研究

为了提高激光探测的方位分辨率，实现对来袭激光的准确定位，选用了FPA-320x256-C型InGaAs焦平面阵列探测器作为光栅衍射型激光告警装置的核心元件。介绍了基于光栅衍射的激光波长和方向探测原理，在分析了探测器性能及参数的基础上设计了驱动电路。探测器在FPGA时序的控制下，输出模拟量通过高速AD进行采集，数据经缓存后存储在FPGA外扩的SRAM中，然后通过USB传送至PC机。上位机Labview采集原始数据，处理并显示。利用上述方法，完成了成像实验，采用波长为1 550和980 nm的激光器从不同角度进行入射，对探测得到的衍射图像进行分析，判断出零级和一级的位置，根据光栅衍射理论，计算出相应波长和二维方向入射角，结果显示波长误差小于10 nm，入射角误差小于1°。

Research on the Neas Infrared Focal Plane Array Detector Imaging Technology Used in the Laser Warning

In order to achieve the incoming laser’s accurate position, it is necessary to improve the detected laser’s direction resolution. The InGaAs focal plane array detector with the type of FPA-320x256-C was selected as the core component of the diffraction grating laser warning device. The detection theory of laser wavelength and direction based on diffraction grating was introduced. The drive circuit was designed through the analysis of the detector’s performance and parameters. Under the FPGA’s timing control, the detector’s analog output was sampled by the high-speed AD. The data was cached to FPGA’s extended SRAM, and then transferred to a PC through USB. Labview on a PC collects the raw data for processing and displaying. The imaging experiments were completed with the above method. With the wavelength of 1550 nm and 980 nm laser from different directions the diffraction images were detected. Through analysis the location of the zero order and one order can be determined. According to the grating diffraction theory, the wavelength and the direction of the two-dimensional angle can be calculated. It indicates that the wavelength error is less than 10 nm, and the angle error is less than 1°.