POLARIZATION-INDEPENDENT, INTEGRATED OPTICAL, ACOUSTICALLY TUNABLE WAVELENGTH FILTERS SWITCHES WITH TAPERED ACOUSTICAL DIRECTIONAL COUPLER

Enhanced sidelobe suppression of the filter characteristics of tunable acousto-optical mode converters in LiNbO3 has been achieved using for the first time tapered acoustical directional couplers. A sidelobe su ppression of more than 15.5 dB could be demonstrated in a single stage device. By combining the mode converter with two integrated optical p olarization splitters a polarization independent filter/wavelength sel ective switch has been fabricated with less than 3 dB intrinsic insert ion loss, a polarization dependence of less than 1 dB, and a sidelobe suppression exceeding 14 dB.