Aluminum-free diode laser delivers 10.6-W continuous-wave output at 980 nm
This month at the IEEE/LEOS Annual Meeting (San Francisco, CA) collaborating research centers will report that they have broken the 10-W continuous-wave (CW) power "barrier" for single-stripe diode lasers emitting at 980 nm (paper #WY6). To produce the record high power, researchers at the Reed Center for Photonics at the University of Wisconsin (Madison, WI) and the Sarnoff Corporation (Princeton, NJ) used aluminum (Al) free structures with a broad, 1.2-µm-wide waveguide. The active region of the device has two indium gallium arsenide (InGaAs) quantum wells, each 7 nm thick, surrounded by 0.6-µm-thick indium gallium arsenic phosphide (InGaAsP) confining layers and InGa¥cladding layers.
The reported CW output power of 10.6 W is the highest achieved from InGaAs quantum-well, single-stripe diode lasers, according to Dan Botez, director of the Reed Center. Such devices, emitting in the 890- to 1100-nm region, are used for pumping various types of solid-state lasers as well as for medical therapies. Although the reported power of the aluminum-free device is only 15% higher than the best previously reported result with an InGaAs/AlGaAs device, the wall-plug efficiency is significantly higher for aluminum-free devices, which have much lower series resistance. For instance, at 9 W of CW output, the new aluminum-free device is 50% more efficient overall--45% versus 30%--than its aluminum-containing counterpart, Bote¥said.