Printer Friendly

Squeezing the noise out of light.

Squeezing the noise out of light

Quantum theory puts a fundamental limit on the precision with which a laser can generate light. This intrinsic randomness in the production of photons limits how much the noise, or fluctuations, in any signal can be lowered. Nevertheless, researchers have developed techniques for "squeezing" light, allowing them to reduce the uncertainty in one particular characteristic of a light wave at the expense of another, which becomes more random. By using the more predictable, or less noisy, component, they can improve the precision of a variety of optical measurements.

At this weekhs International Quantum Electronics Conference in Anaheim, Calif., several groups reported significant advances in squeezing light. In a particular, Prem Kumar and his colleagues at Northwestern University in Evanston, Ill., have reduced the amount of noise caused by the random emission of photons by a record 75 percent. "To our knowledge, this is the highest quantum noise reduction ever observed in any experiment to date," the researchers say. Their method involves splitting pulsed laser light into twin beams and measuring the number of location of photons in one beam, thereby gaining information about the photons in the unaffected twin (SN: 3/10/90, p.151).
COPYRIGHT 1990 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1990, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:quantum theory
Publication:Science News
Date:May 26, 1990
Words:201
Previous Article:Light pipes for sensitive spectroscopy.
Next Article:Interstellar graphite in meteorites.
Topics:


Related Articles
Photon, photon, who's got the photon?
Single-photon interference seen.
Quantum baseball: a baseball analogy illuminates a paradox of quantum mechanics.
Counting photons: squeezing a quantum limit.
Light-induced current in a quantum well.
Faster-than-light time tunnels for photons.
Flipping a quantum mechanical coin.
Instant transport: achieving quantum teleportation in the laboratory.
Light shines in quantum-computing arena.
Light comes to halt again--in a solid. (Physics).

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters