Fourier transform spectroscope with quadrangular common path interferometer

• US 5,495,334 A
• Filed: 07/25/1991
• Issued: 02/27/1996
• Est. Priority Date: 07/26/1990
• Status: Expired due to Fees

• Current Assignee: Japan Science And Technology Corpration
• Original Assignee: Research Development Corporation Of Japan (Japan Science And Technology Agency), Toshiyuki Nagoshi, Tsutomu Ichimura
• Inventors: Nagoshi, Toshiyuki, Inaba, Fumio, Ichimura, Tsutomu
• Primary Examiner(s): Turner, Samuel A.
• Application Number:
  US07/735,740
• Time in Patent Office: 1,678 Days
• Field of Search: 356/346, 356/345
• US Class Current: 356/456
• CPC Class Codes: G01J 2009/0223 Common path interferometry; Point diffraction interferometry
• CPC Class Codes: G01J 3/4532 Devices of compact or symmetric construction G01J3/4531 takes precedence

Abstract

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. The apparatus includes an improvement which consists of an additional imaging optical system which converges a light beam from the specimen so as to enter the beam splitter. The additional imaging optical system is disposed so that an image position is substantially coincident with the position of the second of three mirrors in the apparatus.

Claims

1. A Fourier transform spectroscope with a quadrangular common path interferometer, including a beam splitter, first, second and third reflecting mirrors, an imaging optical system, and a detecting means disposed at a position which is substantially conjugate with said second reflecting mirror with respect to said imaging optical system for detecting a one- or two-dimensional distribution image of interference fringes, said beam splitter and said first to third reflecting mirrors being disposed respectively at the vertices of a quadrangle, said first to third reflecting mirrors being arranged such that a light beam transmitted through said beam splitter is sequentially reflected so as to return to a plane of incidence of said beam splitter, while a light beam reflected from said beam splitter is sequentially reflected in the opposite direction to the above so as to return to a plane of emergence of said beam splitter, whereby a light beam that is first transmitted through said beam splitter and then passed via said first to third reflecting mirrors and transmitted through said beam splitter again is made incident on said imaging optical system, together with a light beam that is first reflected from said beam splitter and then passed via said third to first reflecting mirrors and reflected from said beam splitter again, thereby causing said two light beams to interfere with each other at a position which is substantially conjugate with said second reflecting mirror with respect to said imaging optical system, and the resulting interference fringes are detected with said detecting means and subjected to spatial Fourier transform to thereby obtain a spectral distribution of light from a specimen, wherein the improvement comprises a second imaging optical system which converges a light beam from said specimen so as to enter said beam splitter, said second imaging optical system being disposed so that an imagery position thereof is substantially coincident with the position of said second reflecting mirror.

2. A Fourier transform spectroscope with a quadrangular common path interferometer according to claim 1, wherein said specimen is one that extends perpendicularly to an optical axis of said second imaging optical system.

3. A Fourier transform spectroscope with a quadrangular common path interferometer according to claim 1 or 2, wherein said specimen is a biological specimen.