A mid-IR optical emission spectrometer with a PbSe array detector for analyzing spectral characteristic of IR flares

A mid-IR optical emission spectrometer (mid-IR OES) was designed and constructed to detect the absolute spectral radiant exitance of IR signatures. A 256-array PbSe detector was adopted to analyze the mid-IR emission spectrum from countermeasure flares. The spectral response of the optical emission spectrometer was obtained using a directly heated graphite blackbody. The absolute emissions of their IR signatures were inferred by applying spectral response to the spectrum intensity data. Also, we devised a post processing method for compensating diffraction order overlap in a mid- IR grating spectrometer using an array detector. We confirmed the validity of the compensation method by comparing the signal intensities acquired using the different methods.