Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > 'Cornell dots' make the world's tiniest laser

Schematic (not to scale) of the modified Cornell dot used to create the world's smallest laser. The particle, 44 nanometers in diameter, consists of a silica shell surrounding a 14-nanometer gold core. Energy bouncing between dye molecules and a plasmon oscillation in electrons in the gold amplifies the light output.

Provided/Wiesner Lab, Cornell University
Schematic (not to scale) of the modified Cornell dot used to create the world's smallest laser. The particle, 44 nanometers in diameter, consists of a silica shell surrounding a 14-nanometer gold core. Energy bouncing between dye molecules and a plasmon oscillation in electrons in the gold amplifies the light output. Provided/Wiesner Lab, Cornell University

Abstract:
Researchers have modified nanoparticles known as "Cornell dots" to make the world's tiniest laser -- so small it could be incorporated into microchips to serve as a light source for photonic circuits. The device may also have applications for sensors, solar collectors and in biomedicine.

'Cornell dots' make the world's tiniest laser

Ithaca, NY | Posted on August 18th, 2009

The original Cornell dots, created by Ulrich Wiesner, the Spencer T. Olin Professor of Engineering at Cornell, consist of a core of dye molecules enclosed in a silica shell to create an unusually luminous particle. The new work by researchers at Norfolk (Virginia) State University (NSU), Purdue University and Cornell uses what Wiesner calls "hybrid Cornell dots," which have a gold core surrounded by a silica shell in which dye molecules are embedded.

The research is reported in the Aug. 16 online issue of the journal Nature and will appear in a coming print issue.

Using nanoparticles 44 nanometers (nm -- one billionth of a meter or about three atoms in a row) wide, the device is the smallest nanolaser reported to date, and the first operating in visible light wavelengths, the researchers said.

"This opens an interesting playground in terms of miniaturization," said Wiesner. "For the first time we have a building block a factor of 10 smaller than the wavelength of light."

An optical laser this small is impossible because a laser develops its power by bouncing light back and forth in a tuned cavity whose length must be at least half the wavelength of the light to be emitted. In the first tests of the new device, the light emitted had a wavelength of 531 nm, in the green portion of the visible spectrum.

In a conventional laser, molecules are excited by an outside source of energy, which may be light, electricity or a chemical reaction. Some molecules spontaneously release their energy as photons of light, which bounce back and forth between two reflectors, in turn triggering more molecules to emit photons.

In the new device, dye molecules in the nanoparticle are excited by a pumping laser. A few molecules spontaneously release their added energy to generate a plasmon -- a wave motion of free electrons at an optical frequency -- in the gold core. In the tiny space, the dye molecules and the gold core are coupled by electric fields, explains Purdue co-author Vladimir Shalaev.

Oscillations of the plasmon in turn trigger more dye molecules to release their energy, which further pumps up the plasmon, creating a "spaser" (surface plasmon amplification by stimulated emission of radiation). When the energy of the system reaches a threshold the electric field collapses, releasing its energy as a photon. The size of the core -- 14 nm in diameter -- is chosen to set up a resonance that reinforces a wave corresponding to the desired 531 nm light output.

Tests at NSU indicate that the lasing effect occurs within each Cornell dot and is not a phenomenon of a collection of the nanoparticles working together, making this unquestionably the world's smallest laser.

"Some people argue that the ability to produce a surface plasmon in this way will be even more useful," added NSU professor and lead author Mikhail Noginov. It has been suggested that plasmons could be used to send signals across a microchip at the speed of light -- much faster than electrons in wires -- but in less space than photonic circuits need.

The idea of a spaser was first proposed in 2003 by physicists Mark Stockman at Georgia State University and David Bergman at Tel Aviv University. The theory behind the new approach was developed by Evgenii Narimanov at Purdue.

The work is funded by the National Science Foundation, with additional funding from the U.S. Army Research Office.

####

About Cornell University
Cornell University is a private university located in Ithaca, New York, USA, that is a member of the Ivy League.

With consistent top 15 rankings, Cornell is largely considered one of the preeminent Universities in the world. Cornell counts more than 255,000 living alumni, 28 Rhodes Scholars and 40 Nobel laureates affiliated with the university as faculty or students. The student body consists of over 13,000 undergraduate and 6,000 graduate students from all fifty states and one hundred and twenty-two countries. Cornell produces more graduates that go on to become doctors than any other university in the USA. It also produces the largest number of graduates in the life sciences who continue for Ph.D. degrees, and is ranked fourth in the world in producing the largest number of graduates who go on to pursue Ph.D.s at American institutions. Research is a central element of the university's mission; in 2006 Cornell spent $649 million on research and development. In 2007, Cornell ranked fifth among universities in the U.S. in fund-raising, collecting $406.2 million in private support.

From Wikipedia, the free encyclopedia

For more information, please click here

Contacts:
Media Contact:
Blaine Friedlander
(607) 254-8093


Cornell Chronicle:
Bill Steele
(607) 255-7164

Copyright © Cornell University

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

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Nanomedicine

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

'Electronic skin' could improve early breast cancer detection October 29th, 2014

Tiny carbon nanotube pores make big impact October 29th, 2014

Sensors

Tiny carbon nanotube pores make big impact October 29th, 2014

MEMS & Sensors Technology Showcase: Finalists Announced for MEMS Executive Congress US 2014 October 23rd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Announcements

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

Quantum Dots/Rods

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

QD Vision Wins Prestigious Presidential Green Chemistry Challenge Award from the U.S. Environmental Protection Agency October 16th, 2014

Ultrafast remote switching of light emission October 2nd, 2014

Platinum meets its match in quantum dots from coal: Rice University's cheap hybrid outperforms rare metal as fuel-cell catalyst October 1st, 2014

Nanobiotechnology

Tiny carbon nanotube pores make big impact October 29th, 2014

Molecular beacons shine light on how cells 'crawl' October 27th, 2014

Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future: DNA-based programmable circuits could be more sophisticated, cheaper and simpler to make October 27th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

Solar/Photovoltaic

New solar power material converts 90 percent of captured light into heat: SunShot Project aims to make solar cost competitive October 29th, 2014

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

Dyesol Signs Letter of Intent with Tata Steel October 13th, 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