Linear electro-optic coefficient of a GaAs/Al0.4Ga0.6As phase modulator

Abstract

Phase modulation has been measured in a single mode P-p-n-N GaAs/Al0.4Ga0.6As ridge-waveguide phase modulator. These measurements were performed at a wavelength of 1.31 mun for both TE and TM modes by using a Mach-Zehnder interferometer. Phase-modulation efficiencies are estimated to be 54.9 degrees/V.mm and 39.4 degrees/V.mm for TE and TM modes, respectively. These are the highest efficiencies reported to date for GaAs-based waveguide phase modulators at lambda = 1.31 mun. Finally, the electro-optic coefficient (gamma(41)) of 1.45 x 10(-10) cm/V is extracted from the measured phase shift difference between TE and TM modes.