We have demonstrated record high cw and quasi-cw operation of InP-based 1.5 μm laser arrays (bars) and water-cooled stacks. High-efficiency and high-power operation were achieved through device design optimization including the multi-quantum well design, crystal growth process, doping profile, and material composition. Internal quantum efficiency, mode loss, gain parameters, and temperature sensitivity parameters are reported. Single-stripe devices produced 3 watts of cw output power and 35 percent electrical-to-optical efficiency. We demonstrated 40 watts of cw power from single bars on water-cooled copper-microchannel heatsinks. A stack of 20 bars that were collimated using fast axis microlenses achieved greater than 350 watts of cw power.
Operation of 808-nm laser diode pumps at elevated temperature is crucial to many applications. Reliable operation at high power is limited by high thermal load and low catastrophic optical mirror damage (COMD) threshold at elevated temperature range. We demonstrate high efficiency and high power operation at elevated temperatures with high COMD power. These results were achieved through device design optimization such as growth conditions, doping profile, and materials composition of the quantum-well and other layers. Electrical-to-optical efficiency as high as 62 percent was obtained through lowered threshold current and lowered series resistance and increased slope efficiency. The performance of single broad-area laser diodes scales to that of high power single bars on water-cooled copper micro-channel heatsinks or conductively-cooled CS heatsinks. No reduction in bar performance or significant spectral broadening is seen when these micro-channel coolers are assembled into 6-bar and 18-bar cw stacks for the highest power levels.
The unrelenting demand for ever-higher data transfer rates between computing devices, coupled with the emerging ability to produce robust, monolithic arrays of optical sources and detectors has fueled the development of high-speed parallel optical data links, and created a need for connectorized, parallel, multifiber cable assemblies. An innovative approach to the cable assembly manufacturing process has been developed which incorporates the connector installation process into the cable fabrication process, thus enabling the production of connectorized cable assemblies in a continuous, automated manner. This cable assembly fabrication process, as well as critical details surrounding the process, will be discussed.