Small Fourier Transform Spectroscope Using an Integrated Prism-Scanning Interferometer

Abstract

This paper describes an integrated prism-scanning interferometer that consists of a sliding triangular prism with two mirror surfaces attached to a fixed triangular prism beamsplitter. This design eliminates the effect of ambient air and simplifies the alignment. It also halves the stage moving distance because the optical path difference is doubled as a result of both mirrors moving while the sliding prism is scanning. The volume of the interferometer is 2 cm3. We tested the basic operation. The resolution of 0.14 nm and the accuracy of 0.012 nm are obtained at the wavelength of 1525 nm. This interferometer is a significant step towards the realization of a field-use spectrometer based on Fourier transform spectroscopy.