Research & Development World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE

Flipping a Photonic Shock Wave

By R&D Editors | November 10, 2009

Flipping a Photonic Shock Wave 

Cerenkov radiation in a conventional natural medium
Top: Schematic of Cerenkov radiation in a conventional natural medium with positive refractive index, such as water, in which the radiation falls in a cone in the forward direction.

Bottom: Schematic of backward Cerenkov radiation in a left-handed medium, showing the reversed cone. Courtesy of Alan Stonebraker

A team of physicists has directly observed a reverse shock wave of light in a specially tailored structure known as a left-handed metamaterial. Although it was first predicted over 40 years ago, this is the first unambiguous experimental demonstration of the effect.

Light moving in a vacuum sets the ultimate speed limit, but light travels more slowly through materials like glass and air. Speedy electrons or other charged particles can briefly outrun light in matter, producing a shock wave in the form of a cone of light known as Cerenkov radiation. The eerie blue glow in the cooling water of nuclear reactors is the result of particles moving faster than the speed of light in water. In normal substances, the radiation is emitted in a forward cone. Left-handed metamaterials, however, have unusual effects on light that should reverse the cone’s direction.

two-dimensional experimental configuration and the photographic image of the negative index metamaterials
Schematic of the two-dimensional experimental configuration and the photographic image of the negative index metamaterials used to demonstrate backward Cerenkov radiation. The metamaterials consist of in-plane split-ring resonators and metal wires. Courtesy of Alan Stonebraker

When light enters a normal material like glass, it changes direction, allowing us to make lenses that correct poor vision. When light enters a left-handed metamaterial, the change is opposite to the direction that would occur in normal materials. (The materials are “left-handed” because they affect light oppositely from “right-handed” normal materials.) This means that the cone of Cerenkov radiation from a faster-than-light particle should propagate backward in a left-handed metamaterial. But, experimental difficulties have prevented confirmation of the effect despite its prediction in 1968.

Now, a team of physicists at Zhejiang University in China and the Massachusetts Institute of Technology has developed a new metamaterial structure that successfully demonstrates reverse Cerenkov radiation. Instead of injecting faster-than-light particles into their metamaterial, they created an optical analogue of particles moving at twice light speed. This allowed them to produce a much stronger burst of reverse Cerenkov light than they could have gotten with a real particle beam. Besides verifying a decades-old theoretical prediction, the experiment suggests a new possible application of left-handed metamaterials as detectors of high-speed particles in accelerators and other experiments.

The research is reported in Physical Review Letters and highlighted with a Viewpoint in the November 2, 2009, issue of Physics.

Related Articles Read More >

Why IBM predicts quantum advantage within two years
Aardvark AI forecasts rival supercomputer simulations while using over 99.9% less compute
This week in AI research: Latest Insilico Medicine drug enters the clinic, a $0.55/M token model R1 rivals OpenAI’s $60 flagship, and more
How the startup ALAFIA Supercomputers is deploying on-prem AI for medical research and clinical care
rd newsletter
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, trends, and strategies in Research & Development.
RD 25 Power Index

R&D World Digital Issues

Fall 2024 issue

Browse the most current issue of R&D World and back issues in an easy to use high quality format. Clip, share and download with the leading R&D magazine today.

Research & Development World
  • Subscribe to R&D World Magazine
  • Enews Sign Up
  • Contact Us
  • About Us
  • Drug Discovery & Development
  • Pharmaceutical Processing
  • Global Funding Forecast

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search R&D World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE