RESUMO
A number of acousto-optic figures of merit and elasto-optic constants of a mercury bromide (Hg2Br2) crystal were measured. The key characteristics of the wide-angular acousto-optic tunable filter based on a Hg2Br2 crystal in the (11¯0) plane were calculated from the measurements carried out and previously known data. It is demonstrated that the crystal makes it possible to create effective devices operating in the 5-25 µm wavelength range. In addition, we proposed the design of a filter operating in the long-wavelength infrared range of 8-12 µm, providing spectral resolution up to R=300 and a field of view outside the crystal up to 10°. Its diffraction efficiency can reach up to 2% per 1 W of continuous driving power.
RESUMO
Measurements of the refractive indices and the full set of longitudinal acousto-optical figures of merit in an orthorhombic single-crystal indium iodide (InI) were carried out. The high acousto-optic characteristics (M2 up to 1100×10-15s3kg-1) and strong optical anisotropy (Δn=0.47) make it possible to design various types of high-performance acousto-optic devices of the middle and far-infrared spectral range. In combination with a wide transparency range (0.62-51µm), the obtained characteristics make the crystal extremely promising in comparison with most existing analogs.
RESUMO
The paper proposes a design of acousto-optic cell applying backward collinear interaction and acoustic mode transformation in a KRS-5 crystal. This cell may serve as an acousto-optic tunable filter for far-infrared spectral range and is able to operate both with collimated optical beams and with divergent beams forming images. The problem of acoustic mode transformation by wave reflection from the crystal facet away from symmetry planes has been solved. Polarization properties of the backward collinear interaction in optically isotropic media are discussed.