Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Physicists find right (and left) solution for on-chip optics

Two different devices based on the herringbone pattern were presented in the Science paper: a rectangular array and a ring-shaped array (both interpreted in this illustration). Circularly polarized light with waves that wind in opposite directions gets split by both devices, with its waves routed in opposite directions. For a ring-shaped coupler, this means that plasmons are channeled either toward or away from the center of the structure. Intensity at the center of the ring can therefore be switched on and off by manipulating the polarization of the incoming light. (Image courtesy of Jiao Lin and Samuel Twist.)
Two different devices based on the herringbone pattern were presented in the Science paper: a rectangular array and a ring-shaped array (both interpreted in this illustration). Circularly polarized light with waves that wind in opposite directions gets split by both devices, with its waves routed in opposite directions. For a ring-shaped coupler, this means that plasmons are channeled either toward or away from the center of the structure. Intensity at the center of the ring can therefore be switched on and off by manipulating the polarization of the incoming light. (Image courtesy of Jiao Lin and Samuel Twist.)

Abstract:
A Harvard-led team of researchers has created a new type of nanoscale device that converts an optical signal into waves that travel along a metal surface. Significantly, the device can recognize specific kinds of polarized light and accordingly send the signal in one direction or another.

Physicists find right (and left) solution for on-chip optics

Cambridge, MA | Posted on April 22nd, 2013

The findings, published in the April 19 issue of Science, offer a new way to precisely manipulate light at the subwavelength scale without damaging a signal that could carry data. This opens the door to a new generation of on-chip optical interconnects that can efficiently funnel information from optical to electronic devices.

"If you want to send a data signal around on a tiny chip with lots of components, then you need to be able to precisely control where it's going," says co-lead author Balthasar Müller, a graduate student at the Harvard School of Engineering and Applied Sciences (SEAS). "If you don't control it well, information will be lost. Directivity is such an important factor."

The coupler transforms incoming light into a wave called a surface plasmon polariton, a surface ripple in the sea of electrons that exists inside metals.

In the past, it has been possible to control the direction of these waves by changing the angle at which light strikes the surface of the coupler, but, as Müller puts it, "This was a major pain. Optical circuits are very difficult to align, so readjusting the angles for the sake of routing the signal was impractical."

With the new coupler, the light simply needs to come in perpendicularly, and the device does the rest. Acting like a traffic controller, it reads the polarization of the incoming light wave—which might be linear, left-hand circular, or right-hand circular—and routes it accordingly. The device can even split apart a light beam and send parts of it in different directions, allowing for information transmission on multiple channels.

The coupler consists of a thin sheet of gold, peppered with tiny perforations. But the precise pattern of these slits, arranged rather like herringbones, is where the genius lies.

"The go-to solution until now has been a series of parallel grooves known as a grating, which does the trick but loses a large portion of the signal in the process," says principal investigator Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS. "Now perhaps the go-to solution will be our structure. It makes it possible to control the direction of signals in a very simple and elegant way."

Because the new structure is so small—each repeating unit of the pattern is smaller than the wavelength of visible light—the researchers believe it should be easy to incorporate the design into novel technologies, such as flat optics.

Yet Capasso speaks most animatedly about the possibilities for incorporating the new coupler into future high-speed information networks that may combine nanoscale electronics (which currently exist) with optical and plasmonic elements on a single microchip.

"This has generated great excitement in the field," Capasso says.

Müller and Capasso were joined on this work by co-lead author Jiao Lin, a former SEAS postdoctoral fellow who is now at the Singapore Institute of Manufacturing Technology; and coauthors Qian Wang and Guanghui Yuan, of Nanyang Technological University, Singapore; Nicholas Antoniou, Principal FIB Engineer at the Harvard Center for Nanoscale Systems; and Xiao-Cong Yuan, a professor at the Institute of Modern Optics at Nankai University in China.

The research was supported by the U.S. Air Force Office of Scientific Research, the Agency for Science, Technology, and Research (A*STAR) in Singapore, the National Natural Science Foundation of China, the Ministry of Science and Technology of China, and the National Research Foundation of Singapore. Part of the work was performed at the Harvard Center for Nanoscale Systems, which is a member of the National Nanotechnology Infrastructure Network, supported by the U.S. National Science Foundation.

Full bibliographic information

Jiao Lin et al., "Polarization-Controlled Tunable Directional Coupling of Surface Plasmon Polaritons," SCIENCE, April 19, 2013. DOI: 10.1126/science.1233746

####

About Harvard School of Engineering and Applied Sciences
The Harvard School of Engineering and Applied Sciences (SEAS) serves as the connector and integrator of Harvard's teaching and research efforts in engineering, applied sciences, and technology.

For more information, please click here

Contacts:
Caroline Perry
617-496-1351

Copyright © Harvard School of Engineering and Applied Sciences

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

ANU invention to inspire new night-vision specs December 7th, 2016

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Journal Nanotechnology Progress International (JONPI), newest edition out December 7th, 2016

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Chip Technology

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Optical computing/Photonic computing

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

New method for analyzing crystal structure: Exotic materials called photonic crystals reveal their internal characteristics with new method November 30th, 2016

Novel silicon etching technique crafts 3-D gradient refractive index micro-optics November 28th, 2016

Single photon converter -- a key component of quantum internet November 28th, 2016

Discoveries

ANU invention to inspire new night-vision specs December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Announcements

ANU invention to inspire new night-vision specs December 7th, 2016

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Journal Nanotechnology Progress International (JONPI), newest edition out December 7th, 2016

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Military

ANU invention to inspire new night-vision specs December 7th, 2016

Infrared instrumentation leader secures exclusive use of Vantablack coating December 5th, 2016

Quantum obstacle course changes material from superconductor to insulator December 1st, 2016

New method for analyzing crystal structure: Exotic materials called photonic crystals reveal their internal characteristics with new method November 30th, 2016

Photonics/Optics/Lasers

ANU invention to inspire new night-vision specs December 7th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Controlled electron pulses November 30th, 2016

New method for analyzing crystal structure: Exotic materials called photonic crystals reveal their internal characteristics with new method November 30th, 2016

Research partnerships

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Quantum obstacle course changes material from superconductor to insulator December 1st, 2016

Novel silicon etching technique crafts 3-D gradient refractive index micro-optics November 28th, 2016

Single photon converter -- a key component of quantum internet November 28th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project