Acousto-optic Modulators with a Broadened Frequency Band for Fiber-Optic Lines

The modulator/frequency shifter with single-mode fiber-optic waveguides for a radiation wavelength of 1064 nm has been designed and fabricated. A light beam was focused in the acoustic column center. The switching time of the modulator is 18 ns. The operation mode is pulse and continuous. The total optical losses at the central frequency are −3.2 dB. The expression for the receiving frequency band of the modulator has been obtained. The estimates of 40 MHz are in good agreement with the experimental data. We have shown that the use of the focused-beam scheme makes it possible to realize a modulator with a minimum switching time of 2−3 ns and the receiving frequency band of 200−300 MHz.