Characterizing the polarization features of a multi-prism fused-silica beam expander for a wide-aperture acousto-optic applications

摘要

Practical applications confirm that acousto-optical spectrometers of optical and radio signals provide efficient and accurate processing of data in real time scale. The key component of similar spectrometers is an acousto-optical cell, which dictates performances of the optical scheme arrangement. Within non-collinear arrangement of spectrometer, the most compact and simplest scheme of really wide-aperture light beam expander appears with exploiting an even number of prisms. This arrangement of beam expander does not deflect light beam, provides rather high transmission, and needs less precision for alignment than as a lens telescope requires. We describe a four-prism beam expander providing a 35-time magnification and about 65%-transmission at a distance of 10 cm. Within elliptical polarization, this expander exhibits properties of an amplitude filter being sensitive to the angle of beam incidence. In a view of obtaining the needed eigen-states of elliptical polarization at the output of expander, the detailed analysis of polarization features is performed, numerically estimated, and selectively compared with experimental data.