Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > World's smallest semiconductor laser heralds new era in optical science

A bright point of light from a single plasmon laser emanates from the optical setup used by UC Berkeley researchers (enlarged closeup at right). These semiconductor lasers — the world's smallest — are extremely efficient, so the small amount of scattered light is clearly visible, even in ambient room lighting. Camera saturation of the bright laser light gives the impression of a larger spot. (Courtesy of Xiang Zhang Lab/UC Berkeley)
A bright point of light from a single plasmon laser emanates from the optical setup used by UC Berkeley researchers (enlarged closeup at right). These semiconductor lasers — the world's smallest — are extremely efficient, so the small amount of scattered light is clearly visible, even in ambient room lighting. Camera saturation of the bright laser light gives the impression of a larger spot. (Courtesy of Xiang Zhang Lab/UC Berkeley)

Abstract:
Researchers at the University of California, Berkeley, have reached a new milestone in laser physics by creating the world's smallest semiconductor laser, capable of generating visible light in a space smaller than a single protein molecule.

World's smallest semiconductor laser heralds new era in optical science

Berkeley, CA | Posted on September 1st, 2009

This breakthrough, described in an advanced online publication of the journal Nature on Sunday, Aug. 30, breaks new ground in the field of optics. The UC Berkeley team not only successfully squeezed light into such a tight space, but found a novel way to keep that light energy from dissipating as it moved along, thereby achieving laser action.

"This work shatters traditional notions of laser limits, and makes a major advance toward applications in the biomedical, communications and computing fields," said Xiang Zhang, director at UC Berkeley of a National Science Foundation (NSF) Nanoscale Science and Engineering Center, and head of the research team behind this work

The achievement helps enable the development of such innovations as nanolasers that can probe, manipulate and characterize DNA molecules; optics-based telecommunications many times faster than current technology; and optical computing in which light replaces electronic circuitry with a corresponding leap in speed and processing power.

While it is traditionally accepted that an electromagnetic wave - including laser light - cannot be focused beyond the size of half its wavelength, research teams around the world have found a way to compress light down to dozens of nanometers by binding it to the electrons that oscillate collectively at the surface of metals. This interaction between light and oscillating electrons is known as surface plasmons.

Scientists have been racing to construct surface plasmon lasers that can sustain and utilize these tiny optical excitations. However, the resistance inherent in metals causes these surface plasmons to dissipate almost immediately after being generated, posing a critical challenge to achieving the buildup of the electromagnetic field necessary for lasing.

Zhang, a professor of mechanical engineering, and his research team took a novel approach to stem the loss of light energy by pairing a cadmium sulfide nanowire - 1,000 times thinner than a human hair - with a silver surface separated by an insulating gap of only 5 nanometers, the size of a single protein molecule. In this structure, the gap region stores light within an area 20 times smaller than its wavelength. Because light energy is largely stored in this tiny non-metallic gap, loss is significantly diminished.

With the loss finally under control through this unique "hybrid" design, the researchers could then work on amplifying the light.

"When you are working at such small scales, you do not have much space to play around with," said Rupert Oulton, the research associate in Zhang's lab who first theorized this approach last year and the study's co-lead author. "In our design, the nanowire acts as both a confinement mechanism and an amplifier. It's pulling double duty."

Trapping and sustaining light in radically tight quarters creates such extreme conditions that the very interaction of light and matter is strongly altered, the study authors explained. An increase in the spontaneous emission rate of light is a telltale sign of this altered interaction; in this study, the researchers measured a six-fold increase in the spontaneous emission rate of light in a gap size of 5 nanometers.

Recently, researchers from Norfolk State University reported lasing action of gold spheres in a dye-filled, glasslike shell immersed in a solution. The dye coupled to the gold spheres could generate surface plasmons when exposed to light.

The UC Berkeley researchers used semiconductor materials and fabrication technologies that are commonly employed in modern electronics manufacturing. By engineering hybrid surface plasmons in the tiny gap between semiconductors and metals, they were able to sustain the strongly confined light long enough that its oscillations stabilized into the coherent state that is a key characteristic of a laser.

"What is particularly exciting about the plasmonic lasers we demonstrated here is that they are solid state and fully compatible with semiconductor manufacturing, so they can be electrically pumped and fully integrated at chip-scale," said Volker Sorger, a Ph.D. student in Zhang's lab and study co-lead author.

"Plasmon lasers represent an exciting class of coherent light sources capable of extremely small confinement," said Zhang. "This work can bridge the worlds of electronics and optics at truly molecular length scales."

Scientists hope to eventually shrink light down to the size of an electron's wavelength, which is about a nanometer, or one-billionth of a meter, so that the two can work together on equal footing.

"The advantages of optics over electronics are multifold," added Thomas Zentgraf, a post-doctoral fellow in Zhang's lab and another co-lead author of the Nature paper. "For example, devices will be more power efficient at the same time they offer increased speed or bandwidth."

In addition to the three co-lead authors, other co-authors of the paper are Renmin Ma and Lun Dai from Peking University, and Christopher Gladden and Guy Bartal from Zhang's research group.

This work is supported by the U.S. Air Force Office of Scientific Research and the NSF.

####

About University of California, Berkeley
We teach - educating students at all levels, from undergraduate to the most advanced graduate level. Undergraduate programs are available to all eligible California high-school graduates and community college transfer students who wish to attend the University of California.

Instructional programs at the undergraduate level transmit knowledge and skills to students. At the graduate level, students experience with their instructors the processes of developing and testing new hypotheses and fresh interpretations of knowledge. Education for professional careers, grounded in understanding of relevant sciences, literature and research methods, provides individuals with the tools to continue intellectual development over a lifetime and to contribute to the needs of a changing society.

Through our academic programs, UC helps create an educated workforce that keeps the California economy competitive. And, through University Extension, with a half-million enrollments annually, UC provides continuing education for Californians to improve their job skills and enhance the quality of their lives.

For more information, please click here

Contacts:
Science/Environment/Health/ Technology
Robert Sanders

(510) 643-6998

Copyright © University of California, Berkeley

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

Anousheh Ansari Wins the National Space Society's Space Pioneer Award for "Service to the Space Community" March 5th, 2015

Enhanced Graphene Components for Next Generation Racing Yacht March 5th, 2015

Get ready for NanoDays! March 5th, 2015

American Chemical Society Presidential Symposia: nanoscience, international chemistry March 5th, 2015

Govt.-Legislation/Regulation/Funding/Policy

New research could lead to more efficient electrical energy storage March 4th, 2015

Energy-generating cloth could replace batteries in wearable devices March 4th, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Nanomedicine

Patent for the Novel Cancer Therapies – Ceramide Nanoliposomes March 4th, 2015

Arrowhead to Present at 2015 Barclays Global Healthcare Conference March 4th, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Optical computing/ Photonic computing

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Novel solid-state nanomaterial platform enables terahertz photonics February 17th, 2015

Light in the Moebius strip: A Moebius strip created from laser light opens up new possibilities for material processing and for micro- and nanotechnology February 13th, 2015

Nanoelectronics

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Ultra-thin nanowires can trap electron 'twisters' that disrupt superconductors February 24th, 2015

Improved fire detection with new ultra-sensitive, ultraviolet light sensor February 17th, 2015

Nanotechnology facility planned in Lund, Sweden: A production facility for start-ups in the field of nanotechnology may be built in the Science Village in Lund, a world-class research and innovation village that is also home to ESS, the European Spallation Source February 15th, 2015

Discoveries

Enhanced Graphene Components for Next Generation Racing Yacht March 5th, 2015

American Chemical Society Presidential Symposia: nanoscience, international chemistry March 5th, 2015

Magnetic vortices in nanodisks reveal information: Researchers from Dresden and Jülich use microwaves to read out information from smallest storage devices March 4th, 2015

CiQUS researchers obtain high-quality perovskites over large areas by a chemical method March 4th, 2015

Announcements

Anousheh Ansari Wins the National Space Society's Space Pioneer Award for "Service to the Space Community" March 5th, 2015

Enhanced Graphene Components for Next Generation Racing Yacht March 5th, 2015

Get ready for NanoDays! March 5th, 2015

American Chemical Society Presidential Symposia: nanoscience, international chemistry March 5th, 2015

Nanobiotechnology

Experiment and theory unite at last in debate over microbial nanowires: New model and experiments settle debate over metallic-like conductivity of microbial nanowires in bacterium March 4th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Bacteria network for food: Bacteria connect to each other and exchange nutrients February 23rd, 2015

Building tailor-made DNA nanotubes step by step: New, block-by-block assembly method could pave way for applications in opto-electronics, drug delivery February 23rd, 2015

Photonics/Optics/Lasers

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Breakthrough in OLED technology March 2nd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 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