Featured Research

from universities, journals, and other organizations

Short, on-chip light pulses will enable ultrafast data transfer within computers

Date:
November 25, 2010
Source:
University of California - San Diego
Summary:
Electrical engineers generated short, powerful light pulses on a chip -- an important step toward the optical interconnects that will likely replace the copper wires that carry information between chips within today's computers. Electrical engineers recently developed the first ultra compact, low power pulse compressor on a silicon chip to be described in the scientific literature.

Scanning electron micrograph of dispersive grating before deposition of SiO2 overcladding. This grating enabled electrical engineers to generate short, powerful light pulses on a chip -- an important step toward the optical interconnects that will likely replace the copper wires that carry information between chips within today's computers. University of California, San Diego electrical engineers recently developed the first ultra compact, low power pulse compressor on a silicon chip to be described in the scientific literature. Details appeared online in the journal Nature Communications on Nov. 16.
Credit: UC San Diego / Dawn Tan

Electrical engineers generated short, powerful light pulses on a chip -- an important step toward the optical interconnects that will likely replace the copper wires that carry information between chips within today's computers. University of California, San Diego electrical engineers recently developed the first ultra compact, low power pulse compressor on a silicon chip to be described in the scientific literature.

Details appeared online in the journal Nature Communications on November 16.

This miniaturized short pulse generator eliminates a roadblock on the way to optical interconnects for use in PCs, data centers, imaging applications and beyond. These optical interconnects, which will aggregate slower data channels with pulse compression, will have far higher data rates and generate less heat than the copper wires they will replace. Such aggregation devices will be critical for future optical connections within and between high speed digital electronic processors in future digital information systems.

"Our pulse compressor is implemented on a chip, so we can easily integrate it with computer processors," said Dawn Tan, the Ph.D. candidate in the Department of Electrical and Computer Engineering at UC San Diego Jacobs School of Engineering who led development of the pulse compressor.

"Next generation computer networks and computer architectures will likely replace copper interconnects with their optical counterparts, and these have to be complementary metal oxide semiconductor (CMOS) compatible. This is why we created our pulse compressor on silicon," said Tan, an electrical engineering graduate student researcher at UC San Diego, and part of the National Science Foundation funded Center for Integrated Access Networks.

The pulse compressor will also provide a cost effective method to derive short pulses for a variety of imaging technologies such as time resolved spectroscopy -- which can be used to study lasers and electron behavior, and optical coherence tomography -- which can capture biological tissues in three dimensions.

In addition to increasing data transfer rates, switching from copper wires to optical interconnects will reduce power consumption caused by heat dissipation, switching and transmission of electrical signals.

"At UC San Diego, we recognized the enabling power of nanophotonics for integration of information systems close to 20 years ago when we first started to use nano-scale lithographic tools to create new optical functionalities of materials and devices -- and most importantly, to enable their integration with electronics on a chip. This Nature Communications paper demonstrates such integration of a few optical signal processing device functionalities on a CMOS compatible silicon-on-insulator material platform," said Yeshaiahu Fainman, a professor in the Department of Electrical and Computer Engineering in the UC San Diego Jacobs School of Engineering. Fainman acknowledged DARPA support in developing silicon photonics technologies which helped to enable this work, through programs such as Silicon-based Photonic Analog Signal Processing Engines with Reconfigurability (Si-PhASER) and Ultraperformance Nanophotonic Intrachip Communications (UNIC).

Pulse Compression for On-Chip Optical Interconnects

The compressed pulses are seven times shorter than the original -- the largest compression demonstrated to date on a chip.

Until now, pulse compression featuring such high compression factors was only possible using bulk optics or fiber-based systems, both of which are bulky and not practical for optical interconnects for computers and other electronics.

The combination of high compression and miniaturization are possible due to a nanoscale, light-guiding tool called an "integrated dispersive element" developed and designed primarily by electrical engineering Ph.D. candidate Dawn Tan.

The new dispersive element offers a much needed component to the on-chip nanophotonics tool kit.

The pulse compressor works in two steps. In step one, the spectrum of incoming laser light is broadened. For example, if green laser light were the input, the output would be red, green and blue laser light. In step two, the new integrated dispersive element developed by the electrical engineers manipulates the light so each spectrum in the pulse is travelling at the same speed. This speed synchronization is where pulse compression occurs.

Imagine the laser light as a series of cars. Looking down from above, the cars are initially in a long caravan. This is analogous to a long pulse of laser light. After stage one of pulse compression, the cars are no longer in a single line and they are moving at different speeds. Next, the cars move through the new dispersive grating where some cars are sped up and others are slowed down until each car is moving at the same speed. Viewed from above, the cars are all lined up and pass the finish line at the same moment.

This example illustrates how the on-chip pulse compressor transforms a long pulse of light into a spectrally broader and temporally shorter pulse of light. This temporally compressed pulse will enable multiplexing of data to achieve much higher data speeds.

"In communications, there is this technique called optical time division multiplexing or OTDM, where different signals are interleaved in time to produce a single data stream with higher data rates, on the order of terabytes per second. We've created a compression component that is essential for OTDM," said Tan.

The UC San Diego electrical engineers say they are the first to report a pulse compressor on a CMOS-compatible integrated platform that is strong enough for OTDM.

"In the future, this work will enable integrating multiple 'slow' bandwidth channels with pulse compression into a single ultra-high-bandwidth OTDM channel on a chip. Such aggregation devices will be critical for future inter- and intra-high speed digital electronic processors interconnections for numerous applications such as data centers, field-programmable gate arrays, high performance computing and more," said Fainman, holder of the Cymer Inc. Endowed Chair in Advanced Optical Technologies at the UC San Diego Jacobs School of Engineering and Deputy Director of the NSF-funded Center for Integrated Access Networks.

This work was supported by the Defense Advanced Research Projects Agency, the National Science Foundation (NSF) through Electrical, Communications and Cyber Systems (ECCS) grants, the NSF Center for Integrated Access Networks ERC, the Cymer Corporation and the U.S. Army Research Office.


Story Source:

The above story is based on materials provided by University of California - San Diego. The original article was written by Daniel Kane. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dawn T.H. Tan, Pang C. Sun, Yeshaiahu Fainman. Monolithic nonlinear pulse compressor on a silicon chip. Nature Communications, 2010; 1 (8): 116 DOI: 10.1038/ncomms1113

Cite This Page:

University of California - San Diego. "Short, on-chip light pulses will enable ultrafast data transfer within computers." ScienceDaily. ScienceDaily, 25 November 2010. <www.sciencedaily.com/releases/2010/11/101124143421.htm>.
University of California - San Diego. (2010, November 25). Short, on-chip light pulses will enable ultrafast data transfer within computers. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2010/11/101124143421.htm
University of California - San Diego. "Short, on-chip light pulses will enable ultrafast data transfer within computers." ScienceDaily. www.sciencedaily.com/releases/2010/11/101124143421.htm (accessed September 30, 2014).

Share This



More Matter & Energy News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins