Coded Modulation And Photoelectric Identification Features Of MEMS Infrared Light Sources Array

As an important part of infrared identification device, MEMS infrared light sources arrayhas excellent properties in modulation, permeability, safety and reliability, informationcapacity and so on. These advantages make MEMS infrared light sources array have wideapplications in the field of infrared wireless communication technology, including near-earthspace communications, target search and rescue, battlefield IFF technology etc. With thedevelopment of miniaturization and intelligence of infrared identification device, research onthe encoding, modulation and photoelectric identification characteristics of MEMS infraredlight sources array has attracting more attention.New infrared light sources, with suspending structure and radiator using B-dopedpolycrystalline silicon material, were chosen as the component units of MEMS infrared lightsources array. The radiation characteristics of MEMS infrared light source was researched,array structures were designed and modulated, and then the photoelectric identificationfeatures of array were tested and analyzed systematically.MEMS infrared light sources, which has radiation spectrum at the range of3μm to5μm,and center wavelength of3.6μm, have stable electrical properties with driving voltage from5V to7V. The efficiency of electricity-photology conversion was greater than10%at6V.Plane and three-dimensional structures of array was designed to balance the relationshipbetween the distance and the angle of radiation. The programmable drive circuit for array wasdesigned, and VHDL program has been written to control the three-dimensional structure. Thecode with large information was achieved by the modulation of state transition in time andgraphical changes in space. The information amounts could reach to hundreds of G level. Theeffect of pattern recognition at different external fields had been systematically tested and analyzed, using infrared cameras with different response bands. The graphics changing ofplane or three-dimensional array can be identified at a short distance, and the state of that canbe identified at a minimum distance of2.1km. According to the test results, optimized processto eliminate the affection of twilight during the state transition was put forward, and thesolution to identify the graphics at long distance was proposed. This research makes muchcontribution to the application of MEMS infrared light sources array in infrared wirelesscommunication technology.