Integrated photonics using asymmetric twin-waveguide structures

We demonstrate a number of integrated photonic devices using a twin-waveguide (TG) based technique. The asymmetric TG structure has vertically stacked active and passive waveguides grown in a single epitaxial growth step. All integrated components are defined by post-growth patterning, and tapered mode transformers provide efficient coupling between active and passive sections. Devices made from the same base wafer include single-frequency DBR lasers, semiconductor optical amplifiers and electroabsorption modulators integrated with passive components such as 3 dB couplers, grating sections and Mach-Zehnder interferometers