V. M. Epikhin, L. L. Pal\u2019tsev<\/p>\n
Abstract:<\/b> An acousto-optic modulator based on a TeO2<\/sub> crystal for the frequency range 200\u2013570 MHz with acoustic mode conversion upon reflection from the oblique face of the acousto-optic cell is fabricated and experimentally studied. The modulator operates with a collimated light beam \u223c0.8 mm in diameter, and no beam focusing is required. For a sequence of control signal pulses at f<\/i> > 250 MHz, a sharp (several times) reversible drop in the diffraction efficiency is observed within T<\/i>1<\/sub> = 3 \u2013 20 \u03bcs after the onset of diffraction. The fall time front is shorter than 0.5 \u03bcs. The value of T<\/i>1<\/sub> depends on the control signal parameters. The upper limits of the frequency range of the modulator in the continuous regime and in the regime of a pulse train of the control signal are determined at 360 and 570 MHz, respectively. The attenuation coefficients of the transverse slow acoustic mode in TeO2<\/sub> along the direction of its wave vector, which has an angle of inclination with the [110] axis of 16.80\u00b0, are measured: \u03c3<\/i>(360 MHz) = 1.8 \u00b1 0.4 Np\u00b7cm-1<\/sup>, and \u03c3<\/i>(570 MHz) = 5.5 \u00b1 0.8 Np\u00b7cm-1<\/sup>. The exponent in the frequency dependence \u03c3<\/i>(f<\/i>) \u223c fn<\/sup><\/i> is estimated to be 2.4 \u00b1 0.4. Possibilities and features of the TeO2<\/sub> backscattering experiment are discussed based on the results obtained.<\/p>\n