Jul 30, 2008
Focusing semiconductor lasers usually requires bulky optical lenses acting as a "collimator." Researchers have now demonstrated a plasmonic collimator that utilizes grooves etched directly into the semiconductor laser facet. If the technique is adopted -- Harvard University has applied for a patent on the process -- then semiconductor lasers can be downsized to a bare die without a lens.

Eventually the team at Harvard and Hamamatsu Photonics (Hamamatsu City, Japan) hope to demonstrate electrically-controlled polarization of laser beams for use in spintronics and quantum computing.

"The plasmonic collimator is applicable to all semiconductor lasers," claimed Harvard professor Federico Capasso. "This research opens up using plasmonic structures built on the laser facet to make any desired state of polarization -- the holy grail of spintronics and quantum information processing."