Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clever NIST/JPL technology decodes more information from single photons

13.02.2014
It's not quite Star Trek communications—yet. But long-distance communications in space may be easier now that researchers at the National Institute of Standards and Technology (NIST) and Jet Propulsion Laboratory (JPL) have designed a clever detector array that can extract more information than usual from single particles of light.

Described in a new paper,* the NIST/JPL array-on-a-chip easily identifies the position of the exact detector in a multi-detector system that absorbs an incoming infrared light particle, or photon.


This NIST device, 1.5 by 3 centimeters in outer dimensions, is a prototype receiver for laser communications enabling much higher data rates than conventional systems. Superconducting detectors in the center of the small square chip register the timing and position of single particles of light.

Credit: Verma and Tomlin/NIST

That's the norm for digital photography cameras, of course, but a significant improvement in these astonishingly sensitive detectors that can register a single photon. The new device also records the signal timing, as these particular single-photon detectors have always done.

The technology could be useful in optical communications in space. Lasers can transmit only very low light levels across vast distances, so signals need to contain as much information as possible.

One solution is "pulse position modulation" in which a photon is transmitted at different times and positions to encode more than the usual one bit of information. If a light source transmitted photons slightly to the left/right and up/down, for instance, then the new NIST/JPL detector array circuit could decipher the two bits of information encoded in the spatial position of the photon. Additional bits of information could be encoded by using the arrival time of the photon.

The same NIST/JPL collaboration recently produced detector arrays for the first demonstration of two-way laser communications outside Earth's orbit using the timing version of pulse position modulation.** The new NIST/JPL paper shows how to make an even larger array of detectors for future communications systems.

The new technology uses superconducting nanowire single-photon detectors. The current design can count tens of millions of photons per second but the researchers say it could be scaled up to a system capable of counting of nearly a billion photons per second with low dark (false) counts. The key innovation enabling the latest device was NIST's 2011 introduction of a new detector material, tungsten-silicide, which boosted efficiency, the ability to generate an electrical signal for each arriving photon.*** Detector efficiency now exceeds 90 percent. Other materials are less efficient and would be more difficult to incorporate into complex circuits.

The detectors superconduct at cryogenic temperatures (about minus 270 °C or minus 454 °F), and cooling needs set a limit on wiring complexity. The NIST/JPL scheme requires only twice as many wires (2N) as the number of detectors on one side of a square array (N x N), greatly reducing cooling loads compared to a one-wire-per-detector approach while maintaining high timing accuracy. NIST researchers demonstrated the scheme for a four-detector array with four wires and are now working on a 64-detector array with 16 wires.

In the circuit, each detector is located in a specific column and row of the square array. Each detector acts like an electrical switch. When the detector is in the superconducting state, the switch is closed and the current is equally distributed among all detectors in that column. When a detector absorbs a photon, the switch opens, temporarily diverting the current to an amplifier for the affected column while reducing the signal through the affected row. As a result, the circuit generates a voltage spike in the column readout and a voltage dip in the row readout. The active detector is at the intersection of the active column and row.

The research was supported by the Defense Advanced Research Projects Agency.

V.B. Verma, R. Horansky, F. Marsili, J.A. Stern, M.D. Shaw, A.E. Lita, R.P. Mirin and S.W. Nam. A four-pixel single-photon pulse position camera fabricated from WSi superconducting nanowire single photon detectors. Applied Physics Letters 104, 051115. DOI: 10.1063/1.4864075. Posted online Feb. 4, 2014.

See Oct. 28, 2013, National Aeronautics and Space Administration news release, "Historic Demonstration Proves Laser Communication Possible," at http://www.nasa.gov/content/goddard/historic-demonstration-proves-laser-communication-possible/#.Um62W3Dkvv2.

See 2011 NIST Tech Beat article, "Key Ingredient: Change in Material Boosts Prospects of Ultrafast Single-photon Detector," at http://www.nist.gov/pml/div686/detector-063011.cfm.

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht Earthlike 'Star Wars' Tatooines May Be Common
31.03.2015 | University of Utah

nachricht Dusty substructure in a galaxy far far away
31.03.2015 | Max-Planck-Institut für Astrophysik

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: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Biology in a twist -- deciphering the origins of cell behavior

31.03.2015 | Life Sciences

Wrapping carbon nanotubes in polymers enhances their performance

31.03.2015 | Materials Sciences

Research Links Two Millennia of Cyclones, Floods, El Niño

31.03.2015 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>