Study and analysis of light infrared detection system with dual spectrum and wide temperature range

Because harmonic diffractive optics elements has special achromatism,athermalization and arbitrary phase modulation characteristics,an infrared detection system method with dual spectrum and wide temperature range was presented based on the most advanced infrared dual color detector which had a format of 320×240and the pixel pitch of 30μm.A hybrid refractive/ harmonic diffractive infrared detection system with dual spectrum and wide temperature range was designed.The working wavelength range was 3.8~4.2and 8.8~11.2μm.The system was only consisted of three lenses,including one aspheric surfaces and a harmonic diffraction surface,which made the system have compact structure and light weight.In the temperature range-120~200℃,the RMS radius of spot diagram in 3.8~4.2and 8.8~11.2μm was 19.07and 17.75μm respectively,which is less than the pixel size of infrared detector with 30m,the enclosed energy in 30μm,the enclosed energy in 3.8~4.2and 8.8~ 11.2μm is 88.7%and 82.4%in two pixel size.The method and structure was convenient and predominant.It was proved that the design was feasible.