Design of a Prism to Compensate the Image-shifting Error of the Acousto-optic Tunable Filter

The Acousto-Optic Tunable Filter (AOTF) is a high-speed full-field monochromator which generates two spectrally filtered light beams with ordinary and extraordinary polarization state. The AOTF is widely used to build full-field spectral imaging systems or a spectral domain interferometer. The angle of diffracted light in the AOTF changes according to the scanning of wavelength, which causes an image shift on the CCD plane. An analytic design of a prism system to compensate for the image shift is proposed in this paper. Analysis of light paths in a prism and experimental results verified a proposed compensation method. Experimental results agreed with simulation results based on the suggested prism model. Image shifting errors of ordinary and extraordinary rays were simultaneously minimized at optimal conditions with the designed prism.