Design and laboratory performance of a fiber-fed Fourier transform spectrograph based on off-the-shelf components for astronomical medium and high-resolution spectroscopy

We present the design and performance verification of a fiber-fed Fourier transform spectrograph (FTS) for spectroscopy in the optical band with the ability to reach a maximum optical path difference of 15 mm and allowing for an adjustable spectral resolution (2/A2) between 1 and 15,000. The designed FTS system was successfully constructed using only off-the-shelf optical components. The technique for correction of the phase distortion in the FTS using a metrology interferogram and cubic spline interpolation was investigated and discussed. The contrast performance and the instrument line shape of the FTS were measured and analyzed. To further verify the performance of the developed system, the absorption spectrum of the sunlight was measured and compared with a synthetic model with identified telluric and absorption lines. The result shows that the developed FTS can detect the absorption lines with a spectral resolution close to 15,000. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License.