Spectroscopic Film Coating for the Multi-Prism System

The light sources and receiving devices have different spectral width.For a diode array or CCD,the spectral response at the infrared wavelength,in addit ion to spectroscopic properties in visible light,should be taken into account in the design of a spectroscopic film.This makes the development of the spectrosco pic film complicated.For the increase of measurement accuracy,two multi-prism sy stems in the optics of the newly developed low-latitude meridian circle at Yunna n observatory are adopted to produce multiple light rays for the calibration of the collimator optics from several directions.Since the light source and the dio de array have different spectral response curves,the incident light rays will pa ss through multiple spectroscopic films.In order to obtain the same outcoming sp ectra after the films,different number of medium films are used.