Measurement of the second-order spectral diffraction efficiency of polarized dual-grating spectrometers

Abstract

The diffraction efficiency of dual-grating spectrometers is crucial to the research of spectrometer optical systems, meanwhile it is one of the important indexes for evaluating optical system. The second-order spectral diffraction efficiency of the polarized light has not been thoroughly investigated despite its importance to research on dual-grating spectrometers.However, it affects the imaging quality of the diffractive optical elements, and evaluating of spectrometer optical efficiency. In this work, a test system for the measurement of the second-order spectral diffraction efficiency of polarized light was established. The test system is comprised of a xenon lamp, a collimation system, a polarizer, and a dual-grating spectrometer. The spectral signals of S-and P-polarized light in the band of 285–650 nm were obtained, and the second-order spectral diffraction efficiency measurements of S-and P-polarized light in the band of 285–325 nm were measured. Test results showed that in the 285–325 nm bands, the second-order spectral diffraction efficiency of S-polarized light changed from 30.34% to 4.64%, and that of P-polarized light changed from 3.52% to 0.57%. And the uncertainty of spectrometer system was 2.66%.