512×512 Infrared cryogenic scene projector arrays

Abstract A mosaic array of resistively heated microbridges offers much flexibility for infrared scene simulations. Dynamic scene simulations are important for the testing of the real-time performance capability of IR camera and seeker systems. The excellent thermal properties of the emitter pixels achieved with thin films and unique thermal isolation structures make it possible to achieve high temperatures at power levels ≈ 1 μW per pixel per degree temperature rise. High radiance and high dynamic range are achieved by having pixels with high emissivity and high fill factors, which operate with the substrate and drive electronics at cryogenic temperatures to achieve low background radiance. The thermal time constants of the pixels are defined by material properties and pixel design and are in the millisecond range, making it possible to achieve dynamic frame rates in excess of 100 Hz. Two types of cryogenic resistor arrays have been fabricated and are described, 512×512 arrays with pixels on a 3.5 mil pitch, and 128×128 arrays with pixels on a 2 mil pitch.