Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Single Photon Detector Conquers the Dark Side

13.08.2003


Researchers from the National Institute of Standards and Technology (NIST) and Boston University have demonstrated a detector that counts single pulses of light, while simultaneously reducing false or “dark counts” to virtually zero.



Reported in the July 28, 2003, issue of Applied Physics Letters*, the advance provides a key technology needed for future development of secure quantum communications and cryptography.

Quantum communications and cryptography is a codemaker’s Holy Grail. The idea is to use a rapid series of light pulses (photons) in one of two different states to transmit information in an unbreakable code.


The photon detector project is part of a multi-disciplinary NIST effort to develop the sophisticated measurement methods needed to make quantum communication and cryptography possible. Funding was provided by the Defense Advanced Research Projects Agency (DARPA) and the NIST Advanced Technology Program (ATP).

Most current photon detectors operate best with visible light, cannot reliably detect single photons and suffer from high dark counts due to random electronic noise. The new device operates with the wavelength of near-infrared light used for fiber optic communications and produces negligible dark counts. Instead of using light-sensitive materials, the NIST device uses a tungsten film coupled to a fiber optic communication line. The film is chilled to 120 milliKelvin, at its transition temperature between normal conductivity and superconductivity. When the fiber optic line delivers a photon to the tungsten film, the temperature rises and the apparatus detects it as an increase in electrical resistance.

The device detects about 20,000 photons per second and works with an efficiency of about 20 percent. With planned improvements, the research team hopes to increase efficiencies to greater than 80 percent.

Media Contact:
Fred McGehan (Boulder), (303) 497-3246

* Miller, A.J., Nam, S.W., Martinis, J.M. and Sergienko, A.V. Demonstration of a low-noise near-infrared photon counter with multi-photon discrimination, Applied Physics Letters (July 28, 2003), Vol. 83, No. 4, pp. 791-793.

Fred McGehan | NIST
Further information:
http://www.nist.gov/public_affairs/techbeat/tb2003_0811.htm#photon

More articles from Physics and Astronomy:

nachricht First direct observation and measurement of ultra-fast moving vortices in superconductors
20.07.2017 | The Hebrew University of Jerusalem

nachricht Manipulating Electron Spins Without Loss of Information
19.07.2017 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>