Featured Research

from universities, journals, and other organizations

New Transistor Laser Could Lead To Faster Signal Processing

Date:
November 29, 2004
Source:
University Of Illinois At Urbana-Champaign
Summary:
Researchers at the University of Illinois at Urbana-Champaign have demonstrated the laser operation of a heterojunction bipolar light-emitting transistor. The scientists describe the fabrication and operation of their transistor laser in the Nov. 15 issue of the journal Applied Physics Letters.

The transistor laser light beam with a infrared wavelength labeled "hv" at the top is captured by CCD camera. The contact probes (dark shadow) on the Emitter, Base and Collector.
Credit: Courtesy Milton Feng/Nick Holonyak

CHAMPAIGN, Ill. — Researchers at the University of Illinois at Urbana-Champaign have demonstrated the laser operation of a heterojunction bipolar light-emitting transistor. The scientists describe the fabrication and operation of their transistor laser in the Nov. 15 issue of the journal Applied Physics Letters.

“By incorporating quantum wells into the active region of a light-emitting transistor, we have enhanced the electrical and optical properties, making possible stimulated emission and transistor laser operation,” said Nick Holonyak Jr., a John Bardeen Professor of Electrical and Computer Engineering and Physics at Illinois.

The same principle making possible the transistor – negative and positive charge annihilation in the active region (the source of one of the transistor’s three currents) – has been extended and employed to make a transistor laser, he said. Holonyak invented the first practical light-emitting diode and the first semiconductor laser to operate in the visible spectrum.

Unlike a light-emitting diode, which sends out broadband, incoherent light, the transistor laser emits a narrow, coherent beam. Modulated at transistor speeds, the laser beam could be sent through an optical fiber as a high-speed signal.

“This is a true, three-terminal laser, with an electrical input, electrical output and an optical output, not to mention a coherent optical output,” said Milton Feng, the Holonyak Professor of Electrical and Computer Engineering at Illinois. “It is a device that operates simultaneously as a laser and as a transistor.” Feng is credited with creating the world’s fastest bipolar transistor, a device that operates at a frequency of 509 gigahertz.

At laser threshold – where the light changes from spontaneous emission to stimulated emission – the transistor gain decreases sharply, but still supports three-port operation, Feng said. “The electrical signal goes down, but the optical signal goes up.”

Earlier this year, Feng and Holonyak reported their discovery of a three-port, light-emitting transistor. Building upon that work, the researchers fabricated the transistor laser in the university’s Micro and Nanotechnology Laboratory. Unlike traditional transistors, which are built from silicon and germanium, the transistor laser is made from indium gallium phosphide, gallium arsenide and indium gallium arsenide, but can employ other materials in this family (the so-called III-V compounds).

“This work is still very much in its infancy,” Holonyak said. “There is much more to be learned, including how to separate and optimize the transistor laser output between electrical signals and light signals.”

Down the road, ultra-fast transistor lasers could extend the modulation bandwidth of a semiconductor light source from 20 gigahertz to more than 100 gigahertz. Used as optoelectronic interconnects, transistor lasers could facilitate faster signal processing, higher speed devices and large-capacity seamless communications, as well as a new generation of higher performance electrical and optical integrated circuits.

Co-authors of the paper with Feng and Holonyak are postdoctoral research associate Gabriel Walter and graduate research assistant Richard Chan. The Defense Advanced Research Projects Agency funded the work.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "New Transistor Laser Could Lead To Faster Signal Processing." ScienceDaily. ScienceDaily, 29 November 2004. <www.sciencedaily.com/releases/2004/11/041123210820.htm>.
University Of Illinois At Urbana-Champaign. (2004, November 29). New Transistor Laser Could Lead To Faster Signal Processing. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2004/11/041123210820.htm
University Of Illinois At Urbana-Champaign. "New Transistor Laser Could Lead To Faster Signal Processing." ScienceDaily. www.sciencedaily.com/releases/2004/11/041123210820.htm (accessed July 24, 2014).

Share This




More Matter & Energy News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins