Direct measurement of refractive index and dispersion of optical glass by dual-prism configuration with imaging spectrograph

摘要

We present a simple and precise method based on a dual-prism configuration combined with spectrograph for wavelength-dependent refractive index and absorption measurements in optical glass. This technique measures the angle deviation due to the refractive index difference between two prisms. The refractive indices of dense flint N-SF11 glass from 400 to 650 nm were measured, and the limitations of the system were evaluated. From our results, the three-term Sellmeier coefficients of the glass sample were calculated showing excellent agreement with standard values. (C) 2019 The Japan Society of Applied Physics