Optical Switches Using Active Aluminum Gallium Arsenide/gallium Arsenide Ridge Waveguides

We have investigated active optical switches using AlGaAs/GaAs multiple quantum well single mode ridge waveguide traveling-wave laser amplifiers. The motivation of this project is to provide the feasibility of the active switches for high-speed optical switching system in all-optical networks. We have designed a multiple quantum well layer structure and a single mode ridge waveguide, which was used in these active devices. 1 x 1 (modulator), 1 x 2 (bifurcation switch), 2 x 2 (optical crossbar), 1 x 4 (4-way splitter), and 4 x 4 (reconfigurable switch) active switches have been designed, fabricated and tested. In order to analyze and design the ridge waveguide structure, we have developed a numerical technique, based on an integrated finite-difference method combined with the Amoldi method. The active switches have been fabricated in Microelectronics Laboratory for Research and Education at the University of Minnesota. The switches have been tested for proper switching functions. A 30 dB extinction ratio and 19 GHz bandwidth of small signal modulation response have been obtained from the 1 x 1 switch. 28 dB extinction ratio and power splitting have been achieved in the 1 x 2 switch test. The 2 x 2 switch has demonstrated the crossbar switching function. Due to the package problems, the test of the 1 x 4 and 4 x 4 switch have not been completed. We have demonstrated the feasibility of the active switches. Further studies are needed to enhance the performance of these active switches.