Infrared dynamic scene simulating device based on light down-conversion

The pixelless dynamic scene projector successful in generating high-speed (microsecond range) broadband infrared (hωg, where ω is light frequency, h is Planck´s constant and E_g is the band gap value of the screen material) scenarios through shorter wavelength optical pumping hω>E_g of a semiconductor screen was developed, fabricated, and tested. The device operation principle is based on a possibility of dynamically modulating the apparent temperature (or power emitted in the spectral range of free carrier absorption-emission processes) of an image optically generated on a semiconductor screen (light down-conversion process). The device successfully monitors both hot and cold images (compared to a scene temperature) as well as erase-image and display-hidden-image processes. The results of an experimental study of a germanium screen (300 K < T < 500 K) in the 8-12 μm spectral range are reported for the first time.