Features of the non-linearity specific to two-phonon light scattering controlled by elastic waves with linear losses: potentials for high-resolution spectral analysis.

New physical details inherent in the non-collinear two-phonon Bragg light scattering controlled by ultrahigh frequency elastic waves of finite amplitude are studied in wide-aperture crystals exhibiting moderate linear acoustic losses. Recently, it had been demonstrated that the Bragg regime of light scattering exhibits the specific acousto-optical non-linearity with a set of unit-level maxima. Now, additionally to our previous analysis, we present an advanced analytical description of this phenomenon in the amplitude and frequency domains, and what is more, we orient it mainly at the second unit-level maximum. This non-linearity, together with the linear acoustic losses in an acousto-optical cell, produces a new effect of non-linear apodization. The light beam leaving the cell can suppress the side lobes and grow the dynamic range within the potential optical spectrum analysis. After that, we characterize comprehensively an acousto-optical cell, made of calomel and working within the second maximum of two-phonon light scattering, as a dispersive optical component. Finally, the results of our proof-of-principle experiments with the calomel-made cell operating in the chosen regime are presented and discussed. (C) 2016 Optical Society of America