Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Printed Photonic Crystal Mirrors Shrink On-Chip Lasers Down to Size

24.07.2012
Electrical engineers at The University of Texas at Arlington and at the University of Wisconsin-Madison have devised a new laser for on-chip optical connections that could give computers a huge boost in speed and energy efficiency.

The team published its findings on July 22, 2012 in Nature Photonics.

At just 2 micrometers in height – smaller than the width of a human hair – the surface-emitting laser's vastly lower profile could make it cheaper and easier for manufacturers to integrate high-speed optical data connections into the microprocessors powering the next generation of computers.

Traditionally, edge-emitter lasers are considered as the candidate for on-chip optical links. But since mirrors are hard to form in such lasers and because the lasers occupy a large chip area, researchers have been challenged to find a practical way to monolithically integrate the mirrors on silicon chips.

Surface-emitting lasers necessary for a high-speed optical links between computer cores could be 20 to 30 micrometers tall, slightly bigger than one hole in the mesh of a car’s oil filter. Yet the research team’s engineers say that on a 1.5-micrometer wavelength optically connected chip, lasers of that size dwarf their silicon surroundings.

"It sits tall on the chip, like a tower,” says Zhenqiang Ma, a UW-Madison professor of electrical and computer engineering. “That is definitely not acceptable."

Weidong Zhou, a UT Arlington professor of electrical engineering, says one challenge was integrating light into silicon chips, as silicon itself is not an efficient light emitter.

Zhou and Ma have collaborated to shrink on-chip lasers in recent years with funding from the U.S. Air Force Office of Scientific Research, Army Research Office and Defense Advanced Research Projects Agency.

As a solution, the researchers propose replacing layers and layers of reflectors necessary in the traditional distributed Bragg reflector laser design with two highly reflective photonic crystal mirrors. Composed of compound semiconductor quantum well materials, each mirror is held in place with silicon nanomembranes, extremely thin layers of a silicon.

Zhou says integrating compound semiconductor quantum wells with silicon is a promising approach. “We apply a nanomembrane transfer printing process to accomplish this goal,” he says.

One layer of photonic crystal is equal to about 15 to 30 layers of dielectric reflectors found in conventional lasers. As a result, manufacturers could fabricate 2-micrometer-high lasers for data links with performance that could equal current designs.

In addition to their larger size, reflectors for conventional lasers are made of materials grown only at very high temperatures, which means they can damage the chip they are placed upon during production. Since fabrication via transfer printing can occur at much lower temperatures, Zhou and Ma hope their laser design can be used to place optical links on silicon chips with much less wasted material, time and effort.

Optical data links already exist at the largest scales of data networks – the Internet’s backbone is composed mainly of fiber-optic links between countries, cities and houses. But currently, that data moves over to slower metal connections and wiring as it travels from a regional hub to your house, your computer and eventually between the CPU cores within of the processor powering your machine.

“In the future, you'll see a move to optical at each step,” Ma says. “The last step is within the chip, module to module optical links on the chip itself.”

Through Semerane Inc., the Texas-based startup Zhou and Ma founded, the two hope to implement their production process in functional on-chip photonic crystal membrane lasers that could eventually be part of the next generation high-speed computer processors.

“We believe this laser will be used to make data links more practically available,” Ma says.

“It is truly an interdisciplinary team effort,” Zhou says. “The co-existence of photonics with electronics on the chip level shall enable multi-functional energy-efficient super-chips for applications in computing, communications, sensing, imaging and so on.”

With widespread adoption of processors that use their laser design for optical links, Ma and Zhou could have a hand in increasing the speed along the local leg of the information superhighway.

“Eventually, a CPU core in America could be connected to another CPU core in Asia, with optical connections all along the chain,” Ma says.

Read the full paper here: http://dx.doi.org/

—Mark Riechers, mriechers@engr.wisc.edu, 608-265-8592
—Herb Booth, hbooth@uta.edu, 817-272-7075

Zhenqiang (Jack) Ma | Newswise Science News
Further information:
http://www.wisc.edu

More articles from Power and Electrical Engineering:

nachricht Fraunhofer starts development of refrigerant-free, energy-efficient electrocaloric heat pumps
09.12.2019 | Fraunhofer IPM

nachricht A solution for cleaning up PFAS, one of the world's most intractable pollutants
06.12.2019 | Colorado State University

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: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...

Im Focus: Developing a digital twin

University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making

In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Safer viruses for vaccine research and diagnosis

12.12.2019 | Health and Medicine

NTU Singapore scientists convert plastics into useful chemicals using su

12.12.2019 | Life Sciences

Studies show integrated strategies work best for buffelgrass control

12.12.2019 | Agricultural and Forestry Science

VideoLinks
Science & Research
Overview of more VideoLinks >>>