Temperature Dependence of the Index of Refraction of Fused Silica

TL;DR

This paper presents a simple model to explain how the index of refraction of fused silica varies with temperature, using a single ultraviolet resonance and Kramers-Kronig relations, achieving qualitative agreement with measurements.

Contribution

The paper introduces a new simple model based on a single ultraviolet resonance to explain the temperature dependence of fused silica's refractive index.

Findings

Qualitative agreement with experimental temperature coefficients

Model based on thermal broadening and Kramers-Kronig relations

Highlights limitations in quantitative accuracy

Abstract

In order to explain the positive temperature coefficient of the visible index of refraction of fused silica I develop a simple model which assumes a single ultraviolet resonance. Assuming thermal broadening and using the Kramers- Kronig relations leads to a temperature coefficient in qualitative, but not quantitative, agreement with measurement.