The effects of lateral shifts of the cube corner mirror to the line shape of Fourier transform spectra have been studied. The line distortions that are presented have been detected on many occasions, and one probable cause for them is thermal expansion in the interferometer. A theoretical model for representing this phenomenon is presented. It appears that the positions of the spectral lines are shifted when either of the cube corners is moving at a constant distance from the optical axis of the interferometer. An approximate rule for the line shifts is found, and experimental results are also presented.
