Jamming effect of laser on infrared thermal imager’s automatic gain control circuit

Based on the analysis of the working principle of automatic gain control (AGC) circuit, the mechanism of laser jamming on AGC circuit is discussed, and the experiment of laser jamming on the AGC circuit of an infrared thermal imaging device is carried out. An analysis method which uses the change of regional gray scale to test the gain of AGC circuit is then proposed. Finally, a quantitative analysis is conducted on the experiment data, and the result indicates that, the persistent effective interference of laser on AGC circuit of infrared thermal imaging device can be realized, on condition that the pulse period of interference laser is less than the adjustment time of automatic gain.