Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Flat lens offers a perfect image: Ultrathin wafer of silicon and gold focuses telecom wavelengths without distortion

Left: A micrograph of the flat lens (diameter approximately 1 mm) made of silicon. The surface is coated with concentric rings of gold optical nanoantennas (inset) which impart different delays to the light traversing the lens. Right:The colored rings show the magnitude of the phase delay corresponding to each ring. (Image courtesy of Francesco Aieta.)
Left: A micrograph of the flat lens (diameter approximately 1 mm) made of silicon. The surface is coated with concentric rings of gold optical nanoantennas (inset) which impart different delays to the light traversing the lens. Right:The colored rings show the magnitude of the phase delay corresponding to each ring. (Image courtesy of Francesco Aieta.)

Abstract:
Applied physicists at the Harvard School of Engineering and Applied Sciences (SEAS) have created an ultrathin, flat lens that focuses light without imparting the distortions of conventional lenses.

Flat lens offers a perfect image: Ultrathin wafer of silicon and gold focuses telecom wavelengths without distortion

Cambridge, MA | Posted on August 24th, 2012

At a mere 60 nanometers thick, the flat lens is essentially two-dimensional, yet its focusing power approaches the ultimate physical limit set by the laws of diffraction.

Operating at telecom wavelengths (i.e., the range commonly used in fiber-optic communications), the new device is completely scalable, from near-infrared to terahertz wavelengths, and simple to manufacture. The results have been published online in the journal Nano Letters.

"Our flat lens opens up a new type of technology," says principal investigator Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. "We're presenting a new way of making lenses. Instead of creating phase delays as light propagates through the thickness of the material, you can create an instantaneous phase shift right at the surface of the lens. It's extremely exciting."

Capasso and his collaborators at SEAS create the flat lens by plating a very thin wafer of silicon with an nanometer-thin layer of gold. Next, they strip away parts of the gold layer to leave behind an array of V-shaped structures, evenly spaced in rows across the surface. When Capasso's group shines a laser onto the flat lens, these structures act as nanoantennas that capture the incoming light and hold onto it briefly before releasing it again. Those delays, which are precisely tuned across the surface of the lens, change the direction of the light in the same way that a thick glass lens would, with an important distinction.

The flat lens eliminates optical aberrations such as the "fish-eye" effect that results from conventional wide-angle lenses. Astigmatism and coma aberrations also do not occur with the flat lens, so the resulting image or signal is completely accurate and does not require any complex corrective techniques.

The array of nanoantennas, dubbed a "metasurface," can be tuned for specific wavelengths of light by simply changing the size, angle, and spacing of the antennas.

"In the future we can potentially replace all the bulk components in the majority of optical systems with just flat surfaces," says lead author Francesco Aieta, a visiting graduate student from the Università Politecnica delle Marche in Italy. "It certainly captures the imagination."

####

About Harvard's School of Engineering and Applied Sciences (SEAS)
Aieta’s and Capasso’s coauthors at SEAS included postdoctoral research associates Patrice Genevet and Nanfang Yu (Ph.D. ’09), graduate students Mikhail A. Kats and Romain Blanchard, and visiting scholar Zeno Gaburro.

The work was supported by the National Science Foundation (NSF), the NSF-funded Harvard Nanoscale Science and Engineering Center, and the Center for Nanoscale Systems at Harvard (a member of the NSF-supported National Nanotechnology Infrastructure Network). The researchers also individually received support from the Robert A. Welch Foundation, the European Communities Seventh Framework Programme, and an NSF Graduate Research Fellowship.

For more information, please click here

Contacts:
Caroline Perry
(617) 496-1351

Copyright © Harvard's School of Engineering and Applied Sciences (SEAS)

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

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Govt.-Legislation/Regulation/Funding/Policy

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Laser activated gold pyramids could deliver drugs, DNA into cells without harm: Microstructures create temporary pores in cells March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Discoveries

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Announcements

Tiny sensor lays groundwork for precision X-rays detection via endoscopy:Nanoscale fiber-integrated X-ray sensor opens new doors for medical imaging and radiotherapy March 29th, 2017

Researchers uncover secret of nanomaterial that makes harvesting sunlight easier March 29th, 2017

Information storage with a nanoscale twist: Discovery of a novel rotational force inside magnetic vortices makes it easier to design ultrahigh capacity disk drives March 28th, 2017

ATTOPSEMI Technology Joins FDXcelerator Program to Deliver Advanced Non-Volatile Memory IP to GLOBALFOUNDRIES 22 FDX® Technology Platform: Leading-edge I-fuse™ brings higher reliability, smaller cell size and ease of programmability for consumer, automotive, and IoT applications March 27th, 2017

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

“Cysteine Rose” Wins 2016 Thermo Fisher Scientific Electron Microscopy Image Contest: Thermo Fisher honors Andrea Jacassi of the Italian Institute of Technology for image of cysteine crystals using focused ion beam techniques March 27th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Photonics/Optics/Lasers

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

MIPT physicists predict the existence of unusual optical composites March 10th, 2017

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