Influence of absorption on the refractive index determination accuracy by the minimum deviation method.

By means of computer simulation, the influence of absorption index, κ, on the accuracy of determining the refractive index, n, of optical materials by the minimum deviation method (prism method) is studied at different measuring angular accuracies from 5 to 0.1. The n values within 1.

Specifics of spectral loss measurement in infrared fibers.

Main error sources and their contribution to the total error of measuring the optical loss spectrum by the cut-back method are analyzed in the mid-IR range (2-20 μm) for multimode optical fibers made from materials with high (2-4) refractive index values. It is shown that in case of insufficient fiber length, neglecting the refractive index value leads to a systematic overestimation of the measured optical losses: the higher the refractive index of a fiber core material, the greater an overestimation. The main errors are typically introduced by a bad repeatability of preparation quality of fiber ends and a lower signal-to-noise ratio of mid-IR range experimental setups in comparison with the near-IR range.

Refractive index spectral dependence, Raman spectra, and transmission spectra of high-purity 28Si, 29Si, 30Si, and natSi single crystals.

We performed precise measurement of the refractive index of stable silicon isotopes 28Si, 29Si, and 30Si single crystals with enrichments above 99.9 at.% and a silicon single-crystal natSi of natural isotopic composition with the Fourier-transform interference refractometry method from 1.