Low-Drive Current and Low-Insertion-Loss 1.3 um Microwave Optical Source

This Small Business Innovation Research Phase I project will focus on the development of 20 GHz broad-band 1.3 um optical sources specifically tailored for the microwave user community. Unique advances in epitaxial growth and active region design will be combined with a semiconductor laser device layout configured for both on-wafer microwave testing and flip-chip hybrid integration into a high-speed transistor driver. In addition, a beam expander will be monolithically integrated into the laser chip in order to enhance single-mode-fiber coupling efficiency. These modifications offer the potential to greatly reduce the drive currents required for high-speed laser modulation, enhance the electrical/optical conversion efficiency, and eliminate link losses due to laser/transmission line impedance mismatch. The laser structure will provide the basis for the design and fabrication of a fully (hybrid) integrated, low-insertion-loss microwave optical transmitter module. A second module, containing a new proprietary fiber-pigtailed high-speed 1.2 um semiconductor amplifier, will provide additional flexibility in microwave optical link design.