An ultrahigh-resolution spectrometer using parallel double gratings

Abstract

This paper describes a Parallel-Double-Grating Spectrometer (PDGS) with ultrahigh resolution. Two plane reflection gratings are placed in parallel and staggered to form a dispersive component, through which the light passes multiple times, which greatly improves the dispersion capability of the spectrometer, and therefore the resolution. The diffraction characteristics of the dispersive component and the mathematical model of the PDGS are studied. The results of simulation show that using two reflection gratings with a groove density of 168 gr/mm, combined with spectral splicing technology, the PDGS can achieve a measurement waveband from 450 nm to 610 nm with a resolution better than 30.88 pm. Modifying the structural parameters of the PDGS extends the applicability of the optical path structure to spectral bands from ultraviolet to infrared.