Interferometer compensation for displacement inaccuracies during path length difference altering, method therefor, and fourier transform spectrometer using the same

摘要

An interferometer includes a beam splitter (BS) and two scanning mirrors (M1, M2), which are parallel and disposed on a common slide member that can be linearly displaced. The interferometer further comprises two compensating mirrors (M3, M4), which are disposed between the beam splitter (BS) and the scanning mirrors (M1, M2). The beam splitter (BS) and each of the compensating mirrors (M3, M4) are orthogonal. The interferometer has good tolerance for displacement inaccuracies of the scanning mirrors (M1, M2). The interferometer may be used for producing a compact and inexpensive Fourier transform spectrometer.