US 11,927,483 B2
Fourier spectrophotometer with polarization multiplexing optical system
Yasuyuki Suzuki, Musashino (JP); Yukihiro Nakamura, Musashino (JP); and Tetsushi Namatame, Musashino (JP)
Assigned to Yokogawa Electric Corporation, Tokyo (JP)
Appl. No. 17/771,517
Filed by Yokogawa Electric Corporation, Tokyo (JP)
PCT Filed Oct. 27, 2020, PCT No. PCT/JP2020/040328
§ 371(c)(1), (2) Date Apr. 25, 2022,
PCT Pub. No. WO2021/085442, PCT Pub. Date May 6, 2021.
Claims priority of application No. 2019-196080 (JP), filed on Oct. 29, 2019.
Prior Publication US 2022/0381677 A1, Dec. 1, 2022
Int. Cl. G01J 3/453 (2006.01); G01J 3/02 (2006.01); G01N 21/27 (2006.01); G01N 21/45 (2006.01)
CPC G01J 3/453 (2013.01) [G01J 3/0208 (2013.01); G01J 3/027 (2013.01); G01N 21/274 (2013.01); G01N 21/45 (2013.01); G01N 2021/458 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A Fourier spectrophotometer comprising:
a light source configured to emit light containing a wavelength component in an analysis wavelength band, the analysis wavelength band being a wavelength band in which a spectrum of light passing through a sample as an analysis target is obtained;
an interferometer configured to obtain a first interferogram and a second interferogram whose intensity distributions are inverted from each other as interferograms from the light emitted from the light source, the interferograms being interference light;
a multiplexer configured to multiplex the first interferogram with the second interferogram to irradiate the sample with a resultant interferogram;
a demultiplexer configured to demultiplex the first interferogram and the second interferogram contained in the light passing through the sample;
a light receiver configured to output a first light reception signal obtained by receiving the demultiplexed first interferogram and a second light reception signal obtained by receiving the demultiplexed second interferogram; and
a signal processer configured to perform processing for obtaining a noise-removed spectrum of the wavelength component in the analysis wavelength band by using the first light reception signal and the second light reception signal,
wherein the multiplexer comprises a polarization multiplexing element configured to multiplex the first interferogram in a first polarized state among the first interferograms obtained by the interferometer, with the second interferogram in a second polarized state different from the first polarized state among the second interferograms obtained by the interferometer, and
the demultiplexer comprises a polarization demultiplexing element configured to demultiplex the first interferogram and the second interferogram contained in the light passing through the sample according to polarized states of the first interferogram and the second interferogram.