PtSi IRFPA camera and its application in infrared solar spectrum observation

Although the interest in PtSi infrared focal plane array (IRFPA) has waned due to its low quantum efficiency compared with InSb and HgCdTe arrays, it is very potential in observing brighter celestial objects. We explored the possibility of applying it to the observation of infrared solar spectrum. In the paper, the methods of the simulation and calibration in ou observation are introduced and discussed in detail. Using this kind of camera, a new observational band (FeI 1.56 mu m) is added to the Two-Dimensional Multi-Band Solar Spectrograph at Yunnan Observatory. The dispersion for FeI 1.56 mu m of the new infrared solar spectrograph is 0.0722 angstrom per pixel, and each vertical pixel represents 0.51" of solar disk. It is specially suitable for 2D spectroscopic observation of the deepest solar photosphere. Some primary observation results are also presented.