Abstract
Optical switching of high-bit-rate pulse trains using collinear acoustooptic (AO) devices is theoretically discussed. Since the collinear AO devices have wavelength selectivity, the switched optical pulse trains suffer from distortion when the bandwidth of the pulse train is comparable to the pass bandwidth of the AO device. As the AO device, a sidelobe-suppressed device with a tapered surface-acoustic-wave (SAW) waveguide and a Butterworth-type filter device with a lossy SAW directional coupler are considered. Distortion of optical pulse trains at 40 to 100 Gbps is numerically analyzed. Although filtering characteristics of collinear AO devices for continuous wave or narrow-bandwidth signals have been reported so far, distortion of short pulse trains having wide bandwidth is clarified for the first time.