Precise measurement of refractive index spectral dependence of optical materials for laser, fiber, and integrated optics

Abstract

An interferometric technique for measuring the spectral dependence of the refractive index of solid-state materials to an accuracy of 10−5 over the entire transparency region is described. The possibilities of the technique are demonstrated by the example of new phosphate glasses formulated for laser and fiber optics. It is shown that, in the presence of absorption bands in the transmission spectrum, the technique allows their associated jumps in the refractive index values to be recorded on the order of 10−4−10−5 and below. The shift in the spectral dependence of the refractive index in the region of the absorption band with intensity at 1.7 cm−1 is measured for the first time.