Fourier transformation spectroscope with square interferometer with common path.

摘要

An apparatus for effecting spatial Fourier transform spectroscopic detection of light from a surface luminescent object with high sensitivity by use of a quadrangular common path interferometer comprises a beam splitter (BS) first, second and third reflecting mirrors (M1-M3), a first imaging lents (L2), and a detecting means (D) disposed at a position which is substantially conjugate with the second reflecting mirror (M2) with respect to the first imaging lens (M2), for detecting a one-or two-dimensional distribution image of interference fringes, the beam splitter (BS) and the first to third reflecting mirrors (M1-M3) being disposed respectively at the vertices of a quadrangle, so that the detected interference fringes are subjected to spatial Fourier transform to obtain a spectral distribution of light from a specimen. A light beam from the specimen (1) is converged by a second imaging lens (L) so as to enter the beam splitter (BS), the second imaging lens (L) being disposed so that the focussed image of said specimen (1) is substantially coincident with the position of the second reflecting mirror (M2).