Variation of refractive index with wavelength in fused silica optical fibers and preforms

Abstract

The variation of the refractive index of an unclad fused silica fiber and the preform from which it was pulled was determined over the wavelength range 0.5–1.1 μm, in 0.025‐μm steps. The index is determined from an analysis of the backscattered radiation produced when light from an appropriately filtered xenon‐arc source impinges transversely upon the fiber or preform. The variation of the index of refraction of the fiber follows those of the preform and published values for bulk fused silica material to within 2 parts in 10⁻⁴, with the exception of two points at 0.65 and 0.95 μm.