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

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-parts per million in level, 0.2 nm in wavelength, and 25 mdeg in angle) the retro-reflection and retro-scattering response of both sides of a 2 mm thick silica wafer.