Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Up-Converted Radio: The way to treat radio waves in a noisy environment is to turn them into visible light

In this artist's impression of the device radio waves (green) arrive and are sent to the membrane (center) via gold wires. This induces charge oscillations on the 4-segment electrode right underneath (~1 Ám distance) the membrane. Electric forces thus make the membrane move. This motion is detected with a laser beam (red), with an extreme accuracy (1 femtometer per second measurement time), translating to a very high sensitivity to radio waves. 
Credit: Niels Bohr Institute
In this artist's impression of the device radio waves (green) arrive and are sent to the membrane (center) via gold wires. This induces charge oscillations on the 4-segment electrode right underneath (~1 Ám distance) the membrane. Electric forces thus make the membrane move. This motion is detected with a laser beam (red), with an extreme accuracy (1 femtometer per second measurement time), translating to a very high sensitivity to radio waves.

Credit: Niels Bohr Institute

Abstract:
Ever worry about losing your mobile-phone reception? The problem is a weak microwave signal. The same problem hampers cosmologists looking at the early universe, a glimpse embodied in the cosmic microwave background. Or take a pressing earthly example: oncologists often locate and identify tumors using MRI scans. All three of these efforts---communications, cosmology, medicine---depend on discriminating weak microwave or radio signals from a noisy environment. A new approach to this important problem provides a clean, all-optical detection of microwaves and radiowaves featuring noise mitigation a thousand times better than existing methods.

Up-Converted Radio: The way to treat radio waves in a noisy environment is to turn them into visible light

College Park, MD | Posted on March 7th, 2014

The new detector was just developed by a collaboration of scientists from the Niels Bohr Institute at the University of Copenhagen, the Technical University of Denmark, and the Joint Quantum Institute (1). The building and testing of this first all-optical detection of radio waves is reported in the 6 March 2014 issue of the journal Nature (2).

QUANTUM MICROPHONES

The detector works like this: radio waves strike an antenna which constitutes one element in an electronic circuit. Another element in that circuit is a capacitor, one of whose electrodes consists of a flexible membrane. Light at visible frequencies reflects off the back side of this membrane. Depending on the radio signal arriving just then at the antenna, the silicon-nitride membrane (coated with a 50-nm-thick film of silver) mechanically alters its shape accordingly. This in turn modulates the visible light waves in a consistent way. Thus a radio signal, typically in the megahertz range (106 Hz), can be converted into an optical signal, typically in the hundreds of terahertz range (1014 Hz).

This up-conversion from radio to optical has several advantages. First, it allows a radio signal to be transduced into light and shot down an optical fiber rather than being sent down a copper wire, where it would suffer considerable energy loss. The radio-optical conversion will also help facilitate the development of devices that handle quantum information. In a regular microphone, sound is converted into electrical signals sent down a wire. In the analogous quantum microphone, quantum information could be interconverted between radio and optical waves alternatively for transport or processing.

NOISE ABATEMENT

Second, and no less important, is the mitigation of noise. Radio waves were a boon for communications, starting with Marconi and the first "wireless" transmission of information in the early 20th century. As radio electronics grew in sophistication scientists and engineers became more and more concerned with Johnson noise, the ubiquitous radio noise present by virtue of the simple fact that Earth's surface is a warm place; our world positively glows in radio waves. Named for Bell Labs researcher John B. Johnson, this thermal noise competes with whatever radio signals are being processed in devices. One can amplify a weak signal, but the noise gets amplified along with the signal.

Even more unwanted noise is added in the amplifiers that bring the signal to a level at which it can be processed. For years special transistors have accomplished this task. One major drawback of this approach has been the need to chill the converters to cryogenic temperatures to reach their best performance. One example of this kind of device is the one used on the orbiting Planck Telescope, which maps the microwave background. When the craft's coolant is depleted, the mission ends.

The new device not only produces a much higher degree of noise reduction but it does this at room temperature, thus obviating the need for cryogenics. The development is based upon prior theoretical work by the same collaboration (3). "This device is the first room-temperature transducer of radio waves to optical waves at the quantum level and the first to entail a threefold electrical-mechanical-optical conversion. Previous efforts have bridged the electrical and mechanical or the mechanical and optical, but not all three realms," said the lone JQI participant, theorist Jacob Taylor.

Taylor says that the whole up-conversion process can be done in reverse. Again for the purpose of quantum communication, there might be occasion to convert microwave or radio signals into optical form and then back into radio after transmission from one quantum device to another.

A team leader on the new detector effort is Albert Schliesser of the Niels Bohr Institute in Copenhagen. He describes the detector this way: "In the first place, this is a completely new way to measure electrical signals: making them excite a tiny membrane which we monitor with laser light. It may sound surprising, but this approach is so sensitive that it can out-perform conventional electronic amplifiers. That means, for example, that it could be a new way of getting clearer MRI images, or maps of the sky recorded by radio telescopes. We are currently trying to extend our work---which so far is really just a demonstrator of the concept---to attain a smaller detector which is more sensitive and capable of handling a wider band of radio signals."

(1)The Joint Quantum Institute is operated jointly by the National Institute of Standards and Technology in Gaithersburg, MD and the University of Maryland in College Park.

(2) See Reference Publication Below

####

For more information, please click here

Contacts:
Phillip F. Schewe

(301) 405-0989

RESEARCH CONTACT
Jacob Taylor


Albert Schliesser

Copyright © Joint Quantum Institute

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

REFERENCE PUBLICATION

Related News Press

News and information

Iran to Hold 3rd Int'l Engineering Materials, Metallurgy Conference October 25th, 2014

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Wireless/telecommunications/RF/Antennas

Iranian Scientists Use Nanotechnology to Produce Dielectric Microwave Ceramics October 14th, 2014

Tailored flexible illusion coatings hide objects from detection October 13th, 2014

NIST quantum probe enhances electric field measurements October 8th, 2014

How things coil: Researchers discover that simulation technology designed for Hollywood can be used as a predictive tool for understanding fundamental engineering problems September 29th, 2014

Announcements

Iran to Hold 3rd Int'l Engineering Materials, Metallurgy Conference October 25th, 2014

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

Iranian Scientists Apply Nanotechnology to Produce Surgery Suture October 23rd, 2014

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Photonics/Optics/Lasers

Physicists build reversible laser tractor beam October 20th, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

New VDMA Association "Electronics, Micro and Nano Technologies" founded: Inaugural Meeting in Frankfurt/Main, Germany October 15th, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Quantum nanoscience

NIST quantum probe enhances electric field measurements October 8th, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE