Integrated optic strip waveguide phase modulator driven by a SAW

Single-mode integrated optic strip waveguide phase modulators driven by a surface acoustic wave (SAW) are investigated theoretically and experimentally. Evaluating the overlap integral, a good agreement is obtained between measured and theoretical results. Measurements were performed on ZY-LiNbO3 (z-cut crystal, y-propagating SAW) between 20 MHz and 580 MHz at lambda 0=0.85 mu m optical wavelength using titanium indiffused waveguides. At 9-mW SAW power in an interaction length of 4 mm, optical phase shifts are measured to be 0.32 and 0.112 for transverse magnetic and transverse electric polarization, respectively, at 21.5 MHz.