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 Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously
17.01.2017 | Sonderforschungsbereich 668

nachricht Manchester scientists tie the tightest knot ever achieved
13.01.2017 | University of Manchester

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>