Abstract

Electrooptic III-V directional couplers have been demonstrated both in multiple quantum well (MQW) and bulk systems [1]-[4]. The results indicate that the MQW devices exploiting the quantum-confined Stark effect and other quadratic electrooptic effects have much shorter device lengths as well as lower voltage-length (VL) products than those of the bulk devices. However, MQW devices are wavelength and temperature dependent, and have high propagation losses (~ 20-40 dB/cm) [2]. The linear electrooptic bulk waveguide devices, employing the Pockels effect away from the bandgap, are fairly insensitive to wavelength and temperature changes and are able to exhibit low loss. In this paper, we present a directional coupler electrooptic modulator in epitaxilly-grown bulk AlGaAs/GaAs, for which we have experimentally achieved a voltage-length product of only 7.0 V-mm, and a propagation loss of 3.4 dB/cm at 0.83 μm wavelength.

© 1993 Optical Society of America