Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

A first glimpse inside a macroscopic quantum state March 28th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Chemists make new silicon-based nanomaterials March 27th, 2015

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Possible Futures

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Nanocomposites Market Growth, Industry Outlook To 2020 by Grand View Research, Inc. March 21st, 2015

Nanotechnology Drug Delivery Market in the US 2012-2016 : Latest Report Available by Radiant Insights, Inc March 16th, 2015

Nanomedicine

Novel nanoparticle therapy promotes wound healing March 27th, 2015

Graphene reduces wear of alumina ceramic March 26th, 2015

Application of Graphene Oxide in Body Implants in Iran March 26th, 2015

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Sensors

UW scientists build a nanolaser using a single atomic sheet March 24th, 2015

Iranian Researchers Present Model to Determine Dynamic Behavior of Nanostructures March 24th, 2015

Nanodevice Invented in Iran to Detect Hydrogen Sulfide in Oil, Gas Industry March 20th, 2015

LamdaGen Corporation Launches Taiwan Diagnostic Subsidiary March 19th, 2015

Announcements

A first glimpse inside a macroscopic quantum state March 28th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

Quantum Dots/Rods

Tiny bio-robot is a germ suited-up with graphene quantum dots March 24th, 2015

Rice fine-tunes quantum dots from coal: Rice University scientists gain control of electronic, fluorescent properties of coal-based graphene March 18th, 2015

Ghent University leads large-scale European training project on quantum dots March 13th, 2015

Optical nanoantennas set the stage for a NEMS lab-on-a-chip revolution February 24th, 2015

Nanobiotechnology

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Dolomite’s microfluidics technology ideal for B cell encapsulation March 24th, 2015

Tiny bio-robot is a germ suited-up with graphene quantum dots March 24th, 2015

TGAC's take on the first portable DNA sequencing 'laboratory': First remote laboratory allows researchers to conduct real-time anaylsis March 19th, 2015

Solar/Photovoltaic

LAMDAMAP 2015 hosted by the University March 26th, 2015

SUNY Poly & M+W Make Major Announcement: Major Expansion To Include M+W Owned Gehrlicher Solar America Corporation That Will Create up to 400 Jobs to Develop Solar Power Plants at SUNY Poly Sites Across New York State March 26th, 2015

New kind of 'tandem' solar cell developed: Researchers combine 2 types of photovoltaic material to make a cell that harnesses more sunlight March 24th, 2015

Caltech scientists develop cool process to make better graphene March 18th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE