 |
 |
17 Jun 2002
Making some simple modifications to semiconductor lasers, a pair of University of Rochester researchers have devised a way to make the lasers perform with the power and precision that laser surgeons demand. The work, done by graduate students John Marciante and professor of optics Govind Agrawal, was presented this week at the annual meeting of the Optical Society of America in Rochester.
Although tunability is an attractive feature of semiconductor lasers, their power output is limited by the tendency of their beams to fragment into parallel but weaker beams. The use of such devices traditionally has been limited in surgery, where power and precision are critical. The new laser produces a unified beam no wider than a grain of sand, a fineness the researchers believe is sustainable at up to 12 watts of power, two to four times as powerful as current devices. To achieve this, Agarawl and Marciante use a process known as "filamentation" in which two extra layers of semiconducting material are inserted on either side of the active layer of gallium arsenide, where the beam is formed.
"In filamentation, you get a 'positive' bending in the beams of high-powered semiconductor lasers, but nobody has been able to successfully counteract that with a 'negative bending effect," Marciante said. "The layers we're inserting induce negative bending, resulting in a net bend of zero for the laser beam, keeping it sharply focused."
 |  |  |  |  |  |  |
| © 2025 SPIE Europe |
|
