Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U of T research holds promise for optical chip

29.04.2003


University of Toronto researchers have developed a hybrid plastic that can produce light at wavelengths used for fibre-optic communication, paving the way for an optical computer chip.



The material, developed by a joint team of engineers and chemists, is a plastic embedded with quantum dots - crystals just five billionths of a metre in size - that convert electrons into photons. The findings hold promise for directly linking high-speed computers with networks that transmit information using light - the largest capacity carrier of information available.

"While others have worked in quantum dots before," says investigator Ted Sargent, a professor in the Edward S. Rogers Sr. Department of Electrical and Computer Engineering, "we have shown how quantum dots can be tuned and incorporated into the right materials to address the whole set of communication wavelengths.


"Our study is the first to demonstrate experimentally that we can convert electrical current into light using a particularly promising class of nanocrystals," says Sargent, who holds the Nortel Networks-Canada Research Chair in Emerging Technologies. The study appears in the April 28 issue of the journal Applied Physics Letters.

"Our research is based on nanotechnology: engineering based on the length of a nanometer - one billionth of a metre," he says. "We are building custom materials from the ground up." Working with colleagues in Professor Gregory Scholes’ group from U of T’s Department of Chemistry, the team created nanocrystals of lead sulphide using a cost-effective technique that allowed them to work at room pressure and at temperatures of less than 150 degrees Celsius. Traditionally, creating the crystals used in generating light for fibre-optic communications means working in a vacuum at temperatures approaching 600 to 800 degrees Celsius.

Despite the precise way in which quantum dot nanocrystals are created, the surfaces of the crystals are unstable, Scholes explains. To stabilize them, the team placed a special layer of molecules around the nanocrystals. These crystals were combined with a semiconducting polymer material to create a thin, smooth film of the hybrid polymer.

Sargent explains that when electrons cross the conductive polymer, they encounter what are essentially "canyons," with a quantum dot located at the bottom. Electrons must fall over the edge of the "canyon" and reach the bottom before producing light. The team tailored the stabilizing molecules so they would hold special electrical properties, ensuring a flow of electrons into the light-producing "canyons."

The colours of light the researchers generated, ranging from 1.3 microns to 1.6 microns in wavelength, spanned the full range of colours used to communicate information using light.

"Our work represents a step towards the integration of many fibre-optic communications devices on one chip," says Sargent. "We’ve shown that our hybrid plastic can convert electric current into light, with promising efficiency and with a defined path towards further improvement. With this light source combined with fast electronic transistors, light modulators, light guides and detectors, the optical chip is in view."

The research team included Ludmila Bakueva, Sergei Musikhin, Margaret Hines, Tung-Wah Frederick Chang and Marian Tzolov from the departments of chemistry and electrical and computer engineering. The research was supported by Nortel Networks, the Natural Sciences and Engineering Research Council of Canada, Materials and Manufacturing Ontario, the Canada Foundation for Innovation, the Ontario Innovation Trust and the Canada Research Chairs Program.


CONTACT:

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

Nicolle Wahl
U of T Public Affairs
416-978-6974
nicolle.wahl@utoronto.ca

Nicolle Wahl | EurekAlert!
Further information:
http://www.utoronto.ca/

More articles from Materials Sciences:

nachricht Scientists announce the quest for high-index materials
24.07.2017 | Moscow Institute of Physics and Technology

nachricht ADIR Project: Lasers Recover Valuable Materials
24.07.2017 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>