AT&T BELL LABORATORIES SCIENTISTS MAKE AND OPERATE WORLD'S SMALLEST SEMICONDUCTOR LASER
AT&T BELL LABORATORIES SCIENTISTS MAKE AND OPERATE
WORLD'S SMALLEST SEMICONDUCTOR LASER
SAN JOSE, Calif., Nov. 7 /PRNewswire/ -- AT&T Bell Laboratories scientists reported today that they have made and operated the world's smallest semiconductor lasers.
Seen through a scanning electron microscope, the lasers look like microscopic thumbtacks with the head of each "tack" only 400 atoms thick (about one-thousandth the diameter of a human hair). They are attached to their semiconductor substrate by thin posts.
At least 10,000 of the microscopic lasers, each about five microns in diameter, would fit on the head of a pin.
"These small, fast, low-power microdisk lasers are part of our research effort," said Richard Slusher, head of Bell Labs Optical Physics Research department. "They are directed toward the leading edge of switching and computing technology in years to come."
Designed by Bell Labs Researcher Sam McCall, the lasers operate in what is called a "whispering gallery" mode, named after the sound effect noted in such cathedrals as St. Paul's in London and St. Peter's in Rome, where one can whisper along the wall and be heard all along the inside perimeter of the dome.
Like whispers in these buildings, photons travel with low losses around the edge of the laser. The lasers may be used either as surface- emitting or side-emitting devices.
Each semiconductor disk laser is made of one or more layers of indium gallium arsenide sandwiched between layers of indium gallium arsenide phosphide.
Researchers from three other Bell Labs departments -- Anthony Levi, Semiconductor Physics Research; R. A. Logan, Semiconductor Electronics Research; and S. J. Pearton, Materials and Processing Research -- used metal organic chemical vapor deposition and microlithography to fabricate the tiny disks.
"We have a lot of work ahead of us," said Slusher. "We want to see if these beautiful little structures can meet in a cost-effective manner the many requirements for applications: room-temperature operation, efficient coupling, high yield, very low thresholds, thermal stability, and electrical power drives."
The research team presented a post-deadline paper on the new devices at the annual meeting of the Optical Society of America (OSA) here today, and McCall and his collaborators have written a paper about the microlasers that is scheduled to appear in Applied Physics Letters in January.
Other Bell Labs presentations at OSA include a plenary talk, "Bits and Photons, a Perspective of Optics in Telecommunications," by Herwig Kogelnik, director of the Photonics Research Laboratory, nine other invited papers, 23 submitted papers, and four tutorials.
An additional eight papers and a short course are being presented by Bell Labs scientists at the annual meeting of the IEEE Lasers and Electro-Optics Society, held in conjunction with the OSA meeting.
/Photos available on request./
/CONTACT: Donna C. Cunningham of AT&T Bell Laboratories, 802-482-3748, or home, 802-482-2933/
(T) CO: AT&T Bell Laboratories ST: California IN: CPR SU: KD -- NY082 -- 2347 11/07/91 16:01 EST