Rotatory dispersion in optical activity and a rotary Fourier transform spectrometer

The plane of the vibrating direction of the linearly polarized wave is rotated by propagation of light through a plate composed of an optically active substance in a direction parallel to the optic axis. The optical rotation angle is a function of the wavelength of light. The rotatory dispersion is applied to construct a rotary Fourier transform spectrometer. The optical rotator plate is put between a polarizer and an analyzer. Rotating the analyzer behind the plate and recording the intensity of the transmitted light, one can analyze the spectrum of light by means of the Fourier transform of the intensity. The proposed rotary Fourier transform spectrometer has a simple and stable structure, which can be applied to analyze the spectrum of light from ultraviolet to infrared.