激光捕获系统的信号采集与处理

Signal Acquisition and Processing Technology of Laser Capture System

为了获得高对比度、宽测量范围的InGaAs红外焦平面探测器输出的视频图像,结合成像型激光捕获系统原理分析设计了焦平面探测器与LM98640模数转换芯片的接口电路。首先确定了LM98640的采样模式,并配置其内部参考电平以满足探测器输出信号的转换范围,同时保留一定余量使ADC满足较强激光入射时探测器输出更大范围信号的转换区间。实验结果表明,设计的系统能够实现波长532 nm、1064 nm和1550 nm的激光捕捉,利用软件对光斑图像进行处理可以获得入射激光的具体信息。系统可以实现空间可见光、短波红外范围激光信号的捕捉与识别,解决了较大范围波长内激光的识别问题,提高了输出图像对比度。

In order to obtain the video image output by the InGaAs infrared focal plane detector with high contrast and wide measurement range,the interface circuit of the focal plane detector and the LM98640 analog to digital conversion chip is analyzed by combining with the principle of imaging laser capture system.The sampling mode of the LM98640 is determined,and its internal reference level is configured to meet the conversion range of the detector output signal,and a certain amount of surplus is reserved to make the ADC meet the conversion interval of a larger range of signal during strong laser input.The experimental results show that the designed system can capture lasers whose wavelengths are 532 nm,1064 nm and 1550 nm,and the specific information of the incident laser can be obtained by processing the spot image with software.The system can realize capture and recognition of short-wave infrared and visible light signal in space,which solves the recognition problems of a wide range of wavelength of laser and enhances the contrast of output images.