Spatiospectral structure of wave phase matching in birefringent crystals has a strong dependence on the geometry of the acousto-optic interaction and incident light spectrum. This dependence defines details of light beam profile transformation. It is especially important for imaging applications related to a large angular aperture and a wide spectral bandwidth of the incident light. In this paper, we demonstrate accurate three-dimensional plotting of a light transmission pattern without small birefringence approximation. The rather complicated shape of the phase-matching locus in the spatiospectral domain inevitably leads to residual spatially nonuniform chromatic aberrations in the spectral image. Theoretical consideration and computational modeling are confirmed by the experiments on Bragg diffraction in paratellurite crystal. The results are especially important for the development of acousto-optical imaging devices and laser beam shaping technologies.
We report on wavelength-multiplexed digital holographic imaging based on simultaneous Bragg diffraction of wideband light by several ultrasound waves of different frequencies in crystalline media. This technique is easy to implement, avoids spectral scanning, and is applicable in various digital holography schemes. It also enables single-shot acquisition of a few spectral fringe patterns by a single monochrome sensor and wavelength demultiplexing of the resulting interferogram. We have assembled a Mach–Zehnder interferometer with an acousto-optical tunable filter operating in the multifrequency mode and have validated the proposed technique by dual-, three-, and four-wavelength quantitative phase imaging of the test samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.