Low-coherence interferometric measurement of the spectral dependence of the light field backscattered by optical interfaces

TL;DR

This paper demonstrates a high-resolution method using low-coherence interferometry and Fourier transform spectrometry techniques to characterize the spectral backscattering response of optical interfaces with exceptional precision.

Contribution

It introduces a novel approach combining low coherence interferometry, balanced detection, and Fourier transform spectrometry for detailed spectral characterization of optical interfaces.

Findings

Achieved sub-ppm level sensitivity in measurements

Resolved wavelength with 0.2 nm precision

Measured angular response with 5 mdeg accuracy

Abstract

In this paper, we show how the combined use of low coherence interferometry, balanced detection and data processing comparable to that used in Fourier transform spectrometry allows us to characterize with ultimate resolutions (sub-ppm in level, 0.2 nm in wavelength and 5 mdeg in angle) the retro-reflection and retro-scattering response of both sides of a 2 mm thick silica wafer.