[Electro-optic modulation based study on spectrum resolution of static Fourier transform spectrometer].

In the static interferometer system, the variable refractive crystal LiNbO3 with electro-optic modulation was used in static Fourier transform interferometer, where both sides load phase opposite modulation signal separately so to raise the spectrum resolution in the same size of the instrument by the increment of optical path difference. According to the derivation of the optical path difference function with refraction modulation, the maximum optical path difference was calculated and the spectrum resolution was analyzed to be 16.7 times previous one when the refraction modulation was 0.030 in the same size of interferometer. The simulation result indicated that the refractive modulation would be reduced when the wavelength increased, and the value of optical path difference will be bigger when the chi' increased. In actual detection process, because spectral region 500-1 100 nm is relatively narrow, the spectrum distortion by the wavelength change is not big and may be compensated through the demarcation. This method can increase the optical path difference without mechanical scanning, and possibly raises spectrum resolution of the static interferometer.