Integrated optic strip waveguide phase modulator driven by a SAW

Abstract

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 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ZY</tex> -LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</tex> -cut crystal, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</tex> -propagating SAW) between 20 MHz and 580 MHz at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda_{0} = 0.85 \mu</tex> 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 TM and TE polarization, respectively, at 21.5 MHz.