Featured Research

from universities, journals, and other organizations

University Of Toronto Study Looks Inside 'Beating Heart' Of Lasers

Date:
May 29, 2003
Source:
University Of Toronto
Summary:
A new study by University of Toronto researchers offers the first-ever glimpse inside a laser while it's operating, a breakthrough that could lead to more powerful and efficient lasers for fibre-optic communication systems.

A new study by University of Toronto researchers offers the first-ever glimpse inside a laser while it's operating, a breakthrough that could lead to more powerful and efficient lasers for fibre-optic communication systems. "We've seen the inner workings of a laser in action," says investigator Ted Sargent, a professor in the Edward S. Rogers Sr. Department of Electrical and Computer Engineering. "We've produced a topographical map of the landscape that electrons see as they flow into these lasers to produce light." He says the findings could influence laser design, change the diagnosis of faulty lasers and potentially reduce manufacturing costs. The study, which will appear in the June 9 issue of the journal Applied Physics Letters, offers direct experimental insight into how lasers function, says Sargent, who holds the Nortel Networks-Canada Research Chair in Emerging Technologies.

Lasers are created by growing a complex and carefully designed series of nanometer-sized layers of crystals on a disk of semiconductor material known as a wafer, Sargent explains. Ridges are etched into the crystal surface to guide laser light, thin metal layers are added on top and bottom and the wafer is then cut into tiny cubes or chips. During the laser's operation, an electrical current flows into the chip, providing the energy to generate intense light at a specific wavelength used in fibre-optic communications.

In their study, researchers focused on the "beating heart" portion of the laser (called the active region), where electronic energy is converted into light. Using a technique called scanning voltage microscopy, they examined the surface of an operating laser, picking up differences in voltage. These differences translate to a topographical image of the laser's energy surface, allowing researchers to visualize the forces an electron experiences along its path into the active region, Sargent says.

The team used its newly acquired information about the inside operations of the laser to determine the fraction of electric current that contributed to producing light. The balance of electrons are undesirably diverted from the active region: such current leakage wastes electrons and heats the device up, degrading performance.

"We used direct imaging to resolve a contentious issue in the field: the effectiveness of electronic funnelling into the active region of a ridge-waveguide laser," says Dayan Ban, the U of T doctoral candidate who made the measurements. "Previously, uncorroborated models had fueled speculation by yielding divergent results. Now we know where the electrons go." Ban is now a researcher at the Institute for Microstructural Sciences of the National Research Council of Canada.

"Direct imaging of the functions that drive the action of a living laser could transform how we think about laser 'diagnosis and therapy,'" says Sargent, referring to the measurement and optimization of laser structures and their determination of the devices' inner workings. Currently, designers use a variety of computer simulations to model how lasers work, but the U of T research may determine which simulations are the most accurate design tools. "With accurate models," says Sargent, "the designs we can create are more likely to result in devices that meet design requirements."

Co-investigator St. John Dixon-Warren, a physical chemist from Bookham Technology, a U.K.-based optical components manufacturer located in Kanata, Ont., says their research could also help in diagnosing faulty lasers. "If a particular laser fails," says Dixon-Warren, "the kind of measurements that we are taking could provide some idea of why it failed and the design could then be modified."

Sargent says the findings could have larger implications for the creation of optical circuits for fibre-optic communication. "If we could fully develop these models and fully understand how lasers work, then we could start to build optical circuits with confidence and high probability of success," he says. "Optical chips akin to electronic integrated circuits in computers must be founded on a deep and broad understanding of the processes at work inside current and future generations of lasers."

The research was supported by Nortel Networks Optical Components (recently acquired by Bookham Technology), the Natural Sciences and Engineering Research Council of Canada, the Ontario Research and Development Challenge Fund, the Canada Foundation for Innovation, the Ontario Innovation Trust and the Canada Research Chairs Program.


Story Source:

The above story is based on materials provided by University Of Toronto. Note: Materials may be edited for content and length.


Cite This Page:

University Of Toronto. "University Of Toronto Study Looks Inside 'Beating Heart' Of Lasers." ScienceDaily. ScienceDaily, 29 May 2003. <www.sciencedaily.com/releases/2003/05/030529081109.htm>.
University Of Toronto. (2003, May 29). University Of Toronto Study Looks Inside 'Beating Heart' Of Lasers. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2003/05/030529081109.htm
University Of Toronto. "University Of Toronto Study Looks Inside 'Beating Heart' Of Lasers." ScienceDaily. www.sciencedaily.com/releases/2003/05/030529081109.htm (accessed August 29, 2014).

Share This




More Matter & Energy News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
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