Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U of T Study Looks Inside ’beating Heart’ Of Lasers

28.05.2003


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.

CONTACT:
Ted Sargent
Edward S. Rogers Sr. Department of Electrical and Computer Engineering
416-946-5051
ted.sargent@utoronto.ca

Nicolle Wahl | University of Toronto
Further information:
http://www.utoronto.ca

More articles from Physics and Astronomy:

nachricht First quantum photonic circuit with electrically driven light source
27.09.2016 | Westfälische Wilhelms-Universität Münster

nachricht Australian technology installed on world’s largest single-dish radio telescope
26.09.2016 | International Centre for Radio Astronomy Research (ICRAR)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

The Flexible Grid Involves its Users

27.09.2016 | Information Technology

Process-Integrated Inspection for Ultrasound-Supported Friction Stir Welding of Metal Hybrid-Joints

27.09.2016 | Machine Engineering

First quantum photonic circuit with electrically driven light source

27.09.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>