Optical signal processing in transverse acousto-optic waveguide-type functional devices with SAW

Among several optical devices, fundamental characteristics and processing systems of collinear optical switching device have been studied about optical dielectric waveguides on LiNbO3 crystal substrates. Conventional waveguide-type A-O devices use collinear interaction with mode coupling based on Bragg condition between optical waves and SAW both propagating in same directions. Collinear A-O devices of waveguide-type show sufficient performance for wavelength selective switching with narrow bandwidths in case of low switch speed. However, in these collinear A-O devices, since SAW propagation speed is very slow, interaction time is several micro seconds for 10mm waveguide device length.