New laser structure is a bright idea
Two electrical and computer engineering professors — Philip Dunham Reed Professor Dan Botez and Professor Luke Mawst — have created a nanoscale laser structure to produce more efficient, reliable and stable semiconductor lasers emitting in the mid-infrared within the next two years.
The structure all but eliminates the temperature sensitivity for lasers operating in continuouswave mode, meaning the laser emits uninterrupted, coherent light. These lasers could benefit a wide range of industries, including biomedical devices, environmental monitoring devices, missile avoidance systems and food packaging processes.
Botez and Mawst created the structure via metalorganic chemical vapor deposition, a scalable process that involves exposing a substrate to high heat and chemicals, causing the layers with varying compositions to form on the substrate in an atomic-lattice configuration.
Varied layer composition prevents electrons from escaping the laser structure, a process called carrier leakage. The result will be continuous-wave lasers that the researchers expect to achieve at least 20 percent wall-plug efficiency (the electrical-to-optical power efficiency of a laser system), which would be roughly double the current world record for practical, continuouswave quantum cascade lasers. Botez and Mawst are interested in commercializing the technology, which is covered by two issued and one pending U.S. patents.
For a more detailed story about the structure Botez and Mawst have created, visit www.engr.wisc.edu/news/headlines/ 2009/Dec07.html.