Mitigation of laser dazzle effects on a mid-wave infrared thermal imager by reducing the integration time of the focal plane array

Electro-optical and infrared devices are vulnerable to the increasing threat of dazzle and damage from laser weapons, which will reduce the operational effectiveness of these surveillance devices critical to situational awareness. In this paper, we characterize the impact of laser radiation in-band to a mid-infrared thermal imager. In particular, we stress the importance of the detector integration time as a means to mitigate this threat. An Indium Antimonide focal-plane array of size 640 x 512 pixels was illuminated by a quantum cascade laser operating at a center wavelength of 4.58 micron. The power was increased up to a maximum of approximately 13 milliwatts. Video sequences were recorded for the imager operating at four pre-set integration times that were interlaced at a frame rate of 100 Hz. The extent of the laser dazzle is determined from the images and we assess the resultant impact on the scene contrast. Our results indicate that the spatial extent of the dazzle pattern is reduced as the integration time is also reduced, albeit at the probable detriment to background contrast in the image.