Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonic Chip Work Paves Way for Ultrafast Information Sharing

08.08.2011
Researchers at the California Institute of Technology and the University of California, San Diego have discovered a way to prevent light signals on a silicon chip from reflecting backwards and interfering with its operation.

Otherwise, the light beams would interfere with lasers and other photonic components on the chip and make the chip unstable. The breakthrough marks a significant achievement in the development of integrated photonic chips that could replace electronic chips as the backbone of information technology. Their findings are published Aug. 5 in the journal Science.

Although information systems now rely primarily on fiber optic networks to connect and share data around the world using photons instead of electrons, the underlying computer technology is still based on electronic chips, which are slower and more prone to data loss than photonic chips. Lab versions of photonic chips being developed across the industry are already supporting data transfer rates of 10 gigabits per second, and in just five years, photonic chips could achieve data transfer rates of over 40 Gbps – an order of magnitude higher than the speed of today’s networks. The shift towards optical networks will make information sharing faster, more energy-efficient and less costly.

Electronic chips rely on a diode to isolate electrical signals, enabling current to travel in just one direction and prevent interference. Lead researcher Liang Feng, a postdoctoral fellow at Caltech who earned his doctorate in electrical engineering from the UC San Diego Jacobs School of Engineering in 2010, said engineers have been trying to duplicate the diode system on photonic chips for 20 years.

The Caltech-UC San Diego research team developed a metallic-silicon optical waveguide system to channel light so it travels in different patterns depending on its propagation direction. The pattern is symmetric when traveling forward and asymmetric when reflected backwards along the same path. Similar to the diode in electronics, the backscattered light is dissipated as a result.

“This discovery will help to realize a long-term goal of combining electronics with photonics to enable scalable, energy-efficient and cost-effective technology that will have a tremendous impact on such information systems as supercomputers, the Internet, and data centers,” said Yeshaiahu (Shaya) Fainman, professor and chair of the UC San Diego Department of Electrical and Computer Engineering. “Computer technology will be able to handle a lot more data, faster and at lower cost, which will benefit large-scale business and government users as well as gadget-loving consumers.”

It was during graduate work under the direction of Fainman in 2006, that Feng said he began thinking about how to achieve this kind of “nonreciprocal light propagation” while trying to develop optical metamaterials to manipulate the way light travels.

“Although that particular project was not successful, I never gave up trying to make it work,” said Feng.

He credits the multidisciplinary training he received under Fainman at UCSD – including optics, electromagnetics and physics - for building his knowledge in design, fabrication and measurement that made his discovery possible. So it was inevitable that Feng turned to his former professor, Fainman, and UCSD graduate student Maurice Ayache to conduct the measurement and analysis for the experiment that ultimately proved Feng’s idea works.

The Caltech-UCSD research team is part of the National Science Foundation’s Engineering Research Center for Integrated Access Networks (CIAN) that was created across several institutions – including UCSD’s California Institute for Telecommunications and Information Technology – to develop an all-optical backbone for the next-generation of data centers where messages, images and other chunks of data are aggregated, stored and moved around the world’s computer networks. Funding for this project was provided by the National Science Foundation Engineering Research Centers program and the Defense Advanced Research Projects Agency.

Fainman, who is also deputy director of CIAN, said this research project offers a great example of the interactive and collaborative culture developing among the universities involved in the effort. In this project, Feng and his colleagues at Caltech designed and fabricated the waveguide device while Ayache figured out how to measure the variation of the light beam inside.

The Proof is in the Measurement
Ayache is a Ph.D. candidate in electrical engineering at UCSD. His work on near-field imaging enabled the team to prove that they had in fact realized nonreciprocal propagating light beams as intended. Ayache said he used a near-field scanning optical microscope (NSOM) to capture the light confined inside the waveguide device. The NSOM is part of a heterodyne interferometer which enables it to measure variations of the light wave in space. The experiment showed clearly that the light behaves differently moving in one direction from the other. Ayache compared the NSOM to an “optical stethoscope” enabling the team to see light trapped inside the waveguide device.

“It’s like water in an insulated water pipe,” Ayache said. “You can’t see or hear the water inside, but if you held a stethoscope to the pipe you could hear the current moving and know what’s happening. The integration of NSOM and the interferometer was key to being able to prove that what we thought was going on inside the waveguide was actually going on.”

Ayache said Fainman’s team at UCSD is one of a few groups in the world that have the capability and capacity to combine near-field imaging and heterodyne interferometry to achieve this kind of measurement and analysis of light signals.

The other authors on the paper are Jingquing Huang, a Caltech graduate student; Axel Scherer, professor of electrical engineering, applied physics and physics, and co-director of the Kavli Nanoscience Institute at Caltech; and Ye-Long Xu, Ming-Hiu Lu, and Yan-Feng Chen of the Nanjing National Laboratory of Microstructures in China.

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

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>