Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > First 3D Nanoscale Optical Cavities from Metamaterials: Berkeley Lab Development Holds Promise for Nanolasers, LEDs, Optical Sensors and Photonic Communications

This schematic shows (a) an indefinite metamaterial structure with alternating silver and germanium multilayers; and (b) its iso-frequency contour of light wave vectors with negative refractions along the x- and y-directions, and positive along the z-direction. (Courtesy of Xiang Zhang group)
This schematic shows (a) an indefinite metamaterial structure with alternating silver and germanium multilayers; and (b) its iso-frequency contour of light wave vectors with negative refractions along the x- and y-directions, and positive along the z-direction.

(Courtesy of Xiang Zhang group)

Abstract:
The world's smallest three-dimensional optical cavities with the potential to generate the world's most intense nanolaser beams have been created by a scientific team led by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. In addition to nanolasers, these unique optical cavities with their extraordinary electromagnetic properties should be applicable to a broad range of other technologies, including LEDs, optical sensing, nonlinear optics, quantum optics and photonic integrated circuits.

First 3D Nanoscale Optical Cavities from Metamaterials: Berkeley Lab Development Holds Promise for Nanolasers, LEDs, Optical Sensors and Photonic Communications

Berkeley, CA | Posted on June 27th, 2012

By alternating super-thin multiple layers of silver and germanium, the researchers fabricated an "indefinite metamaterial" from which they created their 3D optical cavities. In natural materials, light behaves the same no matter what direction it propagates. In indefinite metamaterials, light can actually be bent backwards in some directions, a property known as negative refraction. The use of this indefinite metamaterial enabled the scaling down of the 3D optical cavities to extremely deep subwavelength (nanometer) size, resulting in a "hyperboloid iso-frequency contour" of light wave vectors (a measure of magnitude and direction) that supported the highest optical refractive indices ever reported.

This study was directed by Xiang Zhang, a principal investigator with Berkeley Lab's Materials Sciences Division and director of UC Berkeley's Nano-scale Science and Engineering Center (SINAM). He is the corresponding author of a paper describing this research titled "Experimental realization of three-dimensional indefinite cavities at the nanoscale with an anomalous scaling law," which has been published in the journal Nature Photonics. Co-authoring this paper with Zhang were Xiaodong Yang, Jie Yao, Junsuk Rho and Xiaobo Yin.

"Our work opens up a new approach for designing a truly nano-scale optical cavity," Zhang says. "By using metamaterials, we show intriguing cavity physics that counters conventional wisdom. For example, the quality factor of our optical mode rapidly increases with the decrease of cavity size. The results of this study provide us with a tremendous opportunity to develop high performance photonic devices for communications."

Optical cavities are the major components of most lasers. Light confined within an optical cavity will be reflected back and forth between two opposing mirrors to produce a standing wave at a specific resonant frequency. It is from this standing light wave that a laser beam is generated. Optical cavities made from natural materials can be no smaller than the wavelength of the light propagating through them. Metamaterials, however, allow for electromagnetic behavior that is not attainable in nature. Engineered from a combination of metals and dielectrics - insulators that become polarized in the presence of an electromagnetic field - metamaterials derive their optical properties from their structure rather than their chemical composition, as is the case with natural optical materials.

"Due to the unnaturally high refractive index supported in the metamaterials, our 3D cavities can be smaller than one tenth of the optical wavelength," says Xiaodong Yang, lead author of the Nature Photonics paper who is now with the Missouri University of Science and Technology. "At these nanoscale dimensions, optical cavities compress the optical mode into a tiny space, increasing the photon density of states and thereby enhancing the interactions between light and matter."

Another advantage of using indefinite metamaterials to make their 3D optical cavities, Yang says, is that cavities with different sizes can have the same resonance frequency, providing more flexibility in the optical cavity design. Another advantage is that the photons lost when light is reflected back and forth - a problem for optical cavities from natural materials - is reduced as the cavity size gets smaller. Yang says this will benefit the design of future nanoscale lasers.

Germanium was the dielectric chosen to make this metamaterial because it has a relatively high refractive index (about 4.0), compared to air (1.0), which is the dielectric most typically used to make a metamaterial. The alternating layers of silver (20 nanometers thick) and germanium (30 nanometers thick) were cut into cubes of various sizes, depending on the number of metal/dielectric layers. The cube walls tilt into the shape of a trapezoid during the final stage of fabrication with a nano-sized optical cavity in the core.

"The hyperboloid iso-frequency contour of wave vector space in these cavities allowed us to reach very high wave vector values, Yang says. "As wave vector values are proportional to the refractive index, we were able to record optical refractive indices as large as 17.4, which is far beyond that found in natural materials."

This research was supported by the U.S. Department of Air Force Office of Scientific Research.

####

About DOE/Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

For more information, please click here

Contacts:
Lynn Yarris
(510) 486-5375

Copyright © DOE/Lawrence Berkeley National Laboratory

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 Links

For more information about the research of Xiang Zhang visit:

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

State-of-the-art online system unveiled to pinpoint metrology software accuracy March 27th, 2015

Laboratories

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

ORNL-led team demonstrates desalination with nanoporous graphene membrane March 25th, 2015

Los Alamos Offers New Insights Into Radiation Damage Evolution: TUnderstanding defects in materials aids in performance predictions March 18th, 2015

Govt.-Legislation/Regulation/Funding/Policy

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

Novel nanoparticle therapy promotes wound healing March 27th, 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

Discoveries

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

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

Novel nanoparticle therapy promotes wound healing March 27th, 2015

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

Tools

LAMDAMAP 2015 hosted by the University March 26th, 2015

FEI Technology Award of the German Neuroscience Society Goes to Benjamin Judkewitz of the University of Berlin: Bi-annual award honors excellence in brain research during the German Neuroscience Society’s Annual Meeting, held 18-21 March 2015 March 26th, 2015

Square ice filling for a graphene sandwich March 26th, 2015

Nanorobotic agents open the blood-brain barrier, offering hope for new brain treatments March 25th, 2015

Military

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

Novel nanoparticle therapy promotes wound healing March 27th, 2015

Thousands of atoms entangled with a single photon: Result could make atomic clocks more accurate March 26th, 2015

Carbon nanotube fibers make superior links to brain: Rice University invention provides two-way communication with neurons March 25th, 2015

Photonics/Optics/Lasers

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

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

Bar-Ilan U. researchers identify 'tipping point' between quantum and classical worlds: Study sheds new light on 'spooky' quantum optics March 24th, 2015

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

Research partnerships

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

ORNL-led team demonstrates desalination with nanoporous graphene membrane March 25th, 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

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