Abstract

A GaAs traveling-wave electrooptic waveguide polarization modulator In the coplanar strip configuration has been fabricated and characterized at an optical wavelength of 1.3 μm. The –3-dB optical bandwidth is measured to be >20 GHz. The device consists of an optical waveguide with a double-heterojunction structure of Al_0.032Ga_0.968As/GaAs/Al_0.032Ga_0.968As with dimensions of 2, 1.6, and 5 μm, respectively, for vertical confinement and a chemically etched ridge for lateral confinement. The ridge width Is 4.5 pm etched to a depth of 1.2 μm for dielectric loading. The optical waveguide is single mode. The structure is grown by organometallic vapor phase epitaxy at low pressure in a horizontal reactor. All epitaxial layers have doping n < 3 × 10¹⁴ cm⁻³ and are grown on a (001) semi-insulating GaAs substrate.¹

© 1987 Optical Society of America