Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


NIST photon detectors have record efficiency


Sensors that detect and count single photons, the smallest quantities of light, with 88 percent efficiency have been demonstrated by physicists at the National Institute of Standard and Technology (NIST). This record efficiency is an important step toward making reliable single photon detectors for use in practical quantum cryptography systems, the most secure method known for ensuring the privacy of a communications channel.

The four yellow squares in the center of this micrograph are NIST single photon detectors. The top two detectors are 25 by 25 micrometers. The bottom two detectors are 50 by 50 micrometers. The detectors operate with a record 88 percent efficiency. Credit: NIST

Described in the June issue of Physical Review A, Rapid Communications,* the NIST detectors are composed of a small square of tungsten film, 25 by 25 micrometers and 20 nanometers thick, chilled to about 110 milliKelvin, the transition temperature between normal conductivity and superconductivity. When a fiber-optic line delivers a photon to the tungsten film, the temperature rises and results in an increase in electrical resistance. The change in temperature is proportional to the photon energy, allowing the sensor to determine the number of photons in a pulse of monochromatic light.

This type of detector typically has limited efficiency because some photons are reflected from the front surface and others are transmitted all the way through the tungsten. NIST scientists more than quadrupled the detection efficiency over the past two years by depositing the tungsten over a metallic mirror and topping it with an anti-reflective coating, to enable absorption of more light in the tungsten layer.

The NIST sensors operate at the wavelength of near-infrared light used for fiber-optic communications and produce negligible false (or dark) counts. Simulations indicate it should be possible to increase the efficiency well above 99 percent at any wavelength in the ultraviolet to near-infrared frequency range, by building an optical structure with more layers and finer control over layer thickness, according to the paper.

Quantum communications and cryptography systems use the quantum properties of photons to represent 1s and 0s. The NIST sensors could be used as receivers for quantum communications systems, calibration tools for single photon sources, and evaluation tools for testing system security. They also could be used to study the performance of ultralow light optical systems and to test the principles of quantum physics. The work is supported by the Director of Central Intelligence postdoctoral program and the Advanced Research and Development Activity.

Laura Ost | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>