Electrically controlled optical beam-steering/waveguiding in an active GaAs slab

Summary form only given. The effect of carrier induced refractive index change in semiconductor lasers has been studied extensively in the past decade. Owing to the plasma effect, a region that is highly populated with charged carriers experiences a lowering of its refractive index. It is known that when the carrier density in the active region is increased by 10/sup 18/ cm/sup -3/, the refractive index can be depressed by an order of 10/sup -3/. In this report we describe the use of this mechanism to achieve horizontal confinement in a planar GaAs-AlGaAs slab waveguide. Currents are injected via two adjacent contact stripes forming anti-guiding regions immediately underneath the stripes. Light coupled into the channel between the stripes remains confined in that region.