Preventing image information loss of imaging sensors in case of laser dazzle
We present an optical concept for imaging sensor systems, designed to reduce considerably the sensor's image information loss in cases of laser dazzle, based on the principle of complementary bands. For this purpose, the sensor system's spectral range is split in several (at least two) spectral channels, where each channel possesses its own imaging sensor. This long-known principle is applied, for example, in high-quality 3-sensor colour cameras. However, in such camera systems, the spectral separation between the different spectral bands is far too poor to prevent complete sensor saturation when illuminated with intense laser radiation. We increased the channel separation by orders of magnitude by implementing advanced optical elements. Thus, monochromatic radiation of a dazzle laser mainly impacts the dedicated transmitting spectral channel. The other (out-ofband) spectral channels are not or - depending on the laser power - only hardly affected. In this paper, we present our system design as well as a performance evaluation of the sensor concerning laser dazzle.