OPTICAL-PHASE CONJUGATION AND WAVE-GUIDE COUPLING BY CASCADING TRANSVERSE 2ND-HARMONIC AND DIFFERENCE-FREQUENCY-GENERATION IN A VERTICAL-CAVITY

We propose a novel scheme for implementing optical phase conjugation ( OPC) by cascading transverse second-harmonic and difference-frequency generation in a vertical cavity. We propose to achieve phase conjugati on in the pump and input-output two-waveguide structure. For a symmetr ic waveguide structure, the structure can be used as an optical phase conjugate mirror. for a realistic structure based on IIl-V semiconduct or materials, a pump power per unit waveguide of 0.74 W mu m(-1) is re quired to reach a conversion efficiency of similar to 9.4%. Combined w ith another phase-conjugate mirror, the reflectivity of the proposed p hase-conjugate mirror can be efficiently modulated by control of the p ump power. For an asymmetric waveguide structure, a gain is predicted. In addition, by cascading second-harmonic generation (SHG) and parame tric oscillation, we propose to use the same structure as a waveguide coupler. There is a threshold to achieve coupling.