Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Squeezed Through too Small a Hole

Transparent windows are opened in optically thick metallic films perforated with subwavelength holes by adsorbing a thin layer of molecules at the surface. Counterintuitively, transmission occurs at wavelengths at which the molecular layer absorbs strongly (in this case at 700 nm), as revealed by transmission spectra of the hole array without (black curve) and with adsorbed molecules (red).
Transparent windows are opened in optically thick metallic films perforated with subwavelength holes by adsorbing a thin layer of molecules at the surface. Counterintuitively, transmission occurs at wavelengths at which the molecular layer absorbs strongly (in this case at 700 nm), as revealed by transmission spectra of the hole array without (black curve) and with adsorbed molecules (red).

Abstract:
Photon-plasmon coupling: Dye guides light through perforated metal foil

Squeezed Through too Small a Hole

Weinheim, Germany | Posted on January 27th, 2011

Just as photons are bundles of light energy, plasmons are energy packets of plasma oscillations—oscillations of the electron density in a solid body, which are known as surface plasmons when occurring at a metal interface. Surface plasmons introduce new possibilities for the manipulation and transmission of light for applications in a variety of areas, from modern data processing to biomedical sensing. In the journal Angewandte Chemie, Thomas W. Ebbesen, James A. Hutchison, and a team from the University of Strasbourg (France) introduce an interesting new effect based on the coupling of photons and plasmons: dye molecules help light pass through holes in metal foils that are so small that conventional theory predicts the light should not actually be able to pass through at all.

According to classical aperture theory, light should not be able to pass through tiny holes when the diameter is significantly smaller than the wavelength of the light. However, as reported by Ebbesen's group over a decade ago, light transmission can be much higher than predicted for regular arrays of holes owing to the involvement of surface plasmons. In essence, light is converted into surface plasmons, and in this coupled state the photons can pass though the holes to the other side of the metal as plasmons. They can then uncouple and reappear as light.

The French team has now described another phenomenon: if dye molecules are placed directly on the perforated metal surface, they significantly increase its transparence. Contrary to expectation, the additional windows of transparency can occur at wavelengths that are strongly absorbed by the molecules. Interestingly, this also occurs if the arrangement of holes in the foil is irregular; even a single hole is enough.

The researchers propose that two complementary effects are at play. On one hand, the dye molecules in the holes generate a large index variation in the hole favoring the transmission near the absorption band. On the other, the dye molecule generates a kind of "mirror image" of its electric dipole in the metal's free electron plasma, and the dipole and mirror-image dipole interact. If the molecule then absorbs light, it is not re-emitted; instead, the light energy is completely transferred to the metal surface, where it couples with surface plasmons helping the transmission process. This combination enables the light to pass efficiently to the other side of the metal foil.

This discovery represents a new approach for making perforated metal films with tailored transmission of visible light by simply applying a dye that absorbs light with the desired wavelength, which would have application in solar energy technology, filters, and sensing. That the transient excited states of molecules have absorption properties that are very different to their ground state adds a further dynamic dimension to these films, with all-optical, ultra-fast switches another possible application.

Author: Thomas W. Ebbesen, Université de Strasbourg (France), www-isis.u-strasbg.fr/nano/start

Title: Absorption-Induced Transparency

Angewandte Chemie International Edition, Permalink dx.doi.org/10.1002/anie.201006019

####

For more information, please click here

Copyright © Angewandte Chemie International Edition

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

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Nanoscale assembly line August 29th, 2014

New Vice President Takes Helm at CNSE CMOST: Catherine Gilbert To Lead CNSE Children’s Museum of Science and Technology Through Expansion And Relocation August 29th, 2014

Possible Futures

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Academic/Education

New Vice President Takes Helm at CNSE CMOST: Catherine Gilbert To Lead CNSE Children’s Museum of Science and Technology Through Expansion And Relocation August 29th, 2014

RMIT delivers $30m boost to micro and nano-tech August 26th, 2014

SEMATECH and Newly Merged SUNY CNSE/SUNYIT Launch New Patterning Center to Further Advance Materials Development: Center to Provide Access to Critical Tools that Support Semiconductor Technology Node Development August 7th, 2014

Oxford Instruments Asylum Research and the Center for Nanoscale Systems at Harvard University Present a Workshop on AFM Nanomechanical and Nanoelectrical Characterization, Aug. 21-22 August 6th, 2014

Sensors

Copper shines as flexible conductor August 29th, 2014

Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices August 28th, 2014

RMIT delivers $30m boost to micro and nano-tech August 26th, 2014

Symphony of nanoplasmonic and optical resonators leads to magnificent laser-like light emission August 26th, 2014

Discoveries

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Nanoscale assembly line August 29th, 2014

Copper shines as flexible conductor August 29th, 2014

Announcements

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

Nanoscale assembly line August 29th, 2014

New analytical technology reveals 'nanomechanical' surface traits August 29th, 2014

New Vice President Takes Helm at CNSE CMOST: Catherine Gilbert To Lead CNSE Children’s Museum of Science and Technology Through Expansion And Relocation August 29th, 2014

Photonics/Optics/Lasers

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

New analytical technology reveals 'nanomechanical' surface traits August 29th, 2014

Fonon Announces 3D Metal Sintering Technology: Emerging Additive Nano Powder Manufacturing Technology August 28th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Research partnerships

Leading European communications companies and research organizations have launched an EU project developing the future 5th Generation cellular mobile networks August 28th, 2014

New technique uses fraction of measurements to efficiently find quantum wave functions August 28th, 2014

The thunder god vine, assisted by nanotechnology, could shake up future cancer treatment: Targeted therapy for hepatocellular carcinoma using nanotechnology August 27th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Solar/Photovoltaic

Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices August 28th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Eco-friendly 'pre-fab nanoparticles' could revolutionize nano manufacturing: UMass Amherst team invents a way to create versatile, water-soluble nano-modules August 13th, 2014

An Inkjet-Printed Field-Effect Transistor for Label-Free Biosensing August 11th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE