Acousto-optic filter of nonpolarized electromagnetic radiation

An acousto-optic tunable filter that is insensitive to the polarization of incident light is studied both theoretically and experimentally. The fundamental possibility of designing an acousto-optic filter of nonpolarized light is demonstrated. The filter operates in the visible range of electromagnetic waves with λ=480–750 nm and provides a high spatial and temporal resolution. The number of resolvable spots of the filtered image reaches a value of 400×400 with the spectral bandwidth of the device being Δλ=1.7 nm. The results of the processing of optical images formed by arbitrarily polarized light beams are discussed. An acousto-optic filter based on a TeO₂ crystal can be used in optics and spectroscopy in the processing of light beams with an arbitrary polarization, as well as in analyzing optical images formed by light beams whose polarization varies with time.