Narrow bandwidth electrooptic polarization modulator using GaAs quantum-well waveguides

An electrooptic TE-TM polarization converter using a strip-loaded GaAs-AlGaAs multiple quantum well waveguide is discussed. At a wavelength of 870.5 nm, or an energy of approximately 50 meV below the heavy hole exciton resonance, a polarization conversion efficiency of 0.6 degrees /V-mm has been achieved. In addition, a spectral bandwidth of approximately 0.6 nm has been measured for a 3.8-mm-long device. Results indicate that modal birefringence and electroabsorption, due to exciton broadening in the presence of a lateral field, has a significant effect on device efficiency and spectral bandwidth. The mode converter described should be well-suited for use with semiconductor laser diodes in optical signal processing and computing applications.<>