Symmetric Non-Monochromatic Light as Reference in Fourier Transform Spectrometers

Fourier transform spectrometers typically use a presumed monochromatic reference source to track and correct errors in optical path difference changes. This paper will conduct a theoretical analysis to show that nonmonochromatic light sources with symmetric spectral profile can also be used as reference sources without adding any more errors. An experiment was carried out using a symmetric broadband SLED as reference light to measure the spectrum of some other SLED light sources to experimentally demonstrate this finding.