Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electrical Engineers Build “No-Waste” Laser

10.02.2012
A team of University of California, San Diego researchers has built the smallest room-temperature nanolaser to date, as well as an even more startling device: a highly efficient, “thresholdless” laser that funnels all its photons into lasing, without any waste.

The two new lasers require very low power to operate, an important breakthrough since lasers usually require greater and greater “pump power” to begin lasing as they shrink to nano sizes. The small size and extremely low power of these nanolasers could make them very useful components for future optical circuits packed on to tiny computer chips, Mercedeh Khajavikhan and her UC San Diego Jacobs School of Engineering colleagues report in the Feb. 9 issue of the journal Nature.

They suggest that the thresholdless laser may also help researchers as they develop new metamaterials, artificially structured materials that are already being studied for applications from super-lenses that can be used to see individual viruses or DNA molecules to “cloaking” devices that bend light around an object to make it appear invisible.

All lasers require a certain amount of “pump power” from an outside source to begin emitting a coherent beam of light or “lasing,” explained Yeshaiahu (Shaya) Fainman, a professor in the Department of Electrical and Computer Engineering at UC San Diego and co-author of the new study. A laser’s threshold is the point where this coherent output is greater than any spontaneous emission produced.

The smaller a laser is, the greater the pump power needed to reach the point of lasing. To overcome this problem, the UC San Diego researchers developed a design for the new lasers that uses quantum electrodynamic effects in coaxial nanocavities to alleviate the threshold constraint. Like a coaxial cable hooked up to a television (only at a much smaller scale), the laser cavity consists of a metal rod enclosed by a ring of metal-coated, quantum wells of semiconductor material. Khajavikhan and the rest of the team built the thresholdless laser by modifying the geometry of this cavity.

The new design also allowed them to build the smallest room-temperature, continuous wave laser to date. The new room-temperature nanoscale coaxial laser is more than an order of magnitude smaller than their previous record smallest nanolaser published in Nature Photonics less than two years ago. The whole device is almost half a micron in diameter – by comparison, the period at the end of this sentence is nearly 600 microns wide.

These highly efficient lasers would be useful in augmenting future computing chips with optical communications, where the lasers are used to establish communication links between distant points on the chip. Only a small amount of pump power would be required to reach lasing, reducing the number of photons needed to transmit information, said Fainman.

The nanolaser designs appear to be scalable – meaning that they could be shrunk to even smaller sizes – an extremely important feature that makes it possible to harvest laser light from even smaller nanoscale structures, the researchers note. This feature eventually could make them useful for creating and analyzing metamaterials with structures smaller than the wavelength of light currently emitted by the lasers.

Fainman said other applications for the new lasers could include tiny biochemical sensors or high-resolution displays, but the researchers are still working out the theory behind how these tiny lasers operate. They would also like to find a way to pump the lasers electrically instead of optically.

Co-authors for the Nature study, “Thresholdless Nanoscale Coaxial Lasers,” include Mercedeh Khajavikhan, Aleksandar Simic, Michael Kats, Jin Hyoung Lee, Boris Slutsky, Amit Mizrahi, Vitaliy Lomakin, and Yeshaiahu Fainman in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering. The nanolasers are fabricated at the university’s NANO3 facility. The research was funded by the Defense Advanced Research Projects Agency, the National Science Foundation, the NSF Center for Integrated Access Networks (CIAN), the Cymer Corporation and the U.S. Army Research Office.

Catherine Hockmuth | Newswise Science News
Further information:
http://www.ucsd.edu

More articles from Power and Electrical Engineering:

nachricht Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth
20.05.2019 | DOE/Princeton Plasma Physics Laboratory

nachricht New flying/driving robot developed at Ben-Gurion University of the Negev
20.05.2019 | American Associates, Ben-Gurion University of the Negev

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

Im Focus: Recording embryonic development

Scientists develop a molecular recording tool that enables in vivo lineage tracing of embryonic cells

The beginning of new life starts with a fascinating process: A single cell gives rise to progenitor cells that eventually differentiate into the three germ...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Synthesis of helical ladder polymers

21.05.2019 | Materials Sciences

Ultra-thin superlattices from gold nanoparticles for nanophotonics

21.05.2019 | Materials Sciences

Chaperones keep the tumor suppressor protein p53 in check: How molecular escorts help prevent cancer

21.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>