The fast scan sampling method for time modulation FTIR imaging spectrometer

In this paper, the sampling schemes of the time modulation Fourier transform infrared (FTIR) imaging spectrometer are compared and analyzed. Specific implementation solution is proposed for the rapid scan sampling method. Starting from the basic principle of Connes method, the wave length selection of reference laser and the oversampling method are discussed. An improved method which can satisfy high accuracy oversampling and correct counting error is put forward on the basis of traditional method. And a sampling method which is suitable for the time modulation FTIR imaging spectrometer is introduced in optical path design. This method divided the reference laser beam into two beams with fixed phase angle based on traditional reference laser method. And these two beams are utilized to estimate the moving direction of moving mirror and quadruple oversampling. The polarization effects of optical components in Michelson interferometer with hollow retroreflectors are analyzed in this paper. And the depolarization effect of all optical components is analyzed with Jones matrix. On the basis of considering the various optical element polarization characteristics, this method is promoted from plane mirror to hollow retroreflectors that extend the application range of it.