Laser Protection for Day Cameras

Looking at tank architectures over the past 30 years, one thing is obvious; tanks are now studded with optical sights and sensors.Instead of a few periscopes or vision blocks, modern-day tanks have a number of sensors for driving, aiming the gun and controlling a remote weapon.Next-generation tanks and fighting vehicles will have an even greater reliance on optics and sensor systems.The proliferation of multiple laser wavelengths presents a significant danger to ground vehicle vision systems, especially day camera sensors like the one used on the CROWS system.One way to protect viewing systems against fixed frequency lasers is to use narrow band spectral line rejection filters at the known laser wavelengths, attenuating incident laser energy at these wavelengths, thus preventing laser radiation from damaging the sensor. As the number of possible laser wavelengths increases, this approach becomes less practical, because for each wavelength blocked, more and more visible light is attenuated until the system is well-blocked, but useless as a visual system.Our approach is to leverage work being done at AFRL, SA Photonics, and Debye Research in developing a solid state limiter.We have chosen two different materials approaches, which should serve to minimize risk.