A Simple Device For Measuring The Spectral Transmittance Of Lens Used In Ingaas Image Intensifier Apparatus

In this article, in order to accurately measure the spectral transmittance of imaging lens used in InGaAs imaging apparatus, a simple device, which spectrum ranges from 400 nanometers to 2000 nanometers, based on double grating monochromator and self-collimating has been founded by using stable shortwave infrared radiant source, accurate double grating monochromator and telescope, stable silicon detector and cooled HgCdTe infrared detector. An imaging lens whose spectral transmittance has been known is measured on it. Comparing the test results to known data provided by manufacture, it is shown that the testing device founded in this article is competent to measure spectral transmittance of shortwave infrared imaging lens and which max relative deviation is no more than +/- 2.5%. It is worthwhile for selecting InGaAs image intensifier assembly and evaluating the quality of shortwave infrared imaging lens.