Hybrid-integrated 4×4 optical gate matrix switch using silica-based optical waveguides and LD array chips

The fabrication and characteristics of a hybrid-integrated optical gate matrix switch were studied. The switch was composed of a silica-based single-mode guided-wave circuit and two InGaAsP gate array chips, each of which comprised eight laser diode optical gates. The gate array chips were assembled on the guided-wave circuit using a hybrid integration technique. The insertion loss of the fabricated 4×4 matrix switch was scattered among switching paths and ranged from 26 to 33 dB. The switch was applicable to a 400 Mb/s signal system with a bit error rate of 10^-9. The numerical analysis shows that the residual reflectivity at the LD gate and waveguide facets caused the loss scattering among the paths and that reduction of the residual reflectivity is essential for improving the switch characteristics