Up-scale: Frequency converter enables ultra-high sensitivity infrared spectrometry

August 26, 2009

In what may prove to be a major development for scientists in fields ranging from forensics to quantum communications, researchers at the National Institute of Standards and Technology (NIST) have developed a new, highly sensitive, low-cost technique for measuring light in the near-infrared range. The technique can measure the spectrum of the specific wavelengths of near infrared light used widely in telecommunications as well as the very weak infrared light at single-photon levels given off by fragile biomaterials and nanomaterials. They described their results in a recent issue of Optics Express.*

A single photon detector is the key device needed to build highly sensitive instruments for measuring spectra. For the past 30 years, scientists have made steady progress increasing the efficiency and sensitivity of visible and ultraviolet photon detectors while methods for detecting elusive single photons in the near-infrared (NIR) range have faltered. The methods presently in use are too static-laden, inefficient and slow, or depend on superconducting detectors, which require expensive, low-temperature operating environments. The NIST group, Lijun Ma, Oliver Slattery and Xiao Tang, wanted to develop a way to use existing detectors such as avalanche photodiode detectors (APD), which work very well for detecting visible light and are widely used, but are ineffective for the detection of NIR.

Their approach was to adapt a technique developed two years ago at NIST for quantum cryptography that "up converts" photons at one frequency to a higher frequency. The technique promotes the infrared photons up to the visible range using a strong, tunable laser. During the frequency conversion process, the narrow-band pump laser scans the infrared signal photons and converts only those that have the desired polarization and wavelength to visible light. Once converted to visible light, the signal photons are easily detected by commercially available APDs. According to Tang, the new system enables the measurement of spectra with sensitivity of more than 1,000 times that of common commercial optical spectral instruments.

"Our key achievement here was to reduce the noise, but our success would not have been possible without the many years of work by others in this field," says Tang. "We hope that our discovery will open doors for researchers studying diseases, pharmaceuticals, secure communications and even solving crimes. We are very excited to make this technology available to the larger scientific community."
-end-
* L. Ma, O. Slattery and X. Tang. Experimental study of high sensitivity infrared spectrometer with waveguide-based up-conversion detector. Optics Express. Vol. 17, No. 16. Aug. 3, 2009.

National Institute of Standards and Technology (NIST)

Related Photons Articles from Brightsurf:

An electrical trigger fires single, identical photons
Researchers at Berkeley Lab have found a way to generate single, identical photons on demand.

Single photons from a silicon chip
Quantum technology holds great promise: Quantum computers are expected to revolutionize database searches, AI systems, and computational simulations.

Physicists "trick" photons into behaving like electrons using a "synthetic" magnetic field
Scientists have discovered an elegant way of manipulating light using a ''synthetic'' Lorentz force -- which in nature is responsible for many fascinating phenomena including the Aurora Borealis.

Scientists use photons as threads to weave novel forms of matter
New research from the University of Southampton has successful discovered a way to bind two negatively charged electron-like particles which could create opportunities to form novel materials for use in new technological developments.

The nature of nuclear forces imprinted in photons
IFJ PAN scientists together with colleagues from the University of Milano (Italy) and other countries confirmed the need to include the three-nucleon interactions in the description of electromagnetic transitions in the 20O atomic nucleus.

Pushing photons
UC Santa Barbara researchers continue to push the boundaries of LED design a little further with a new method that could pave the way toward more efficient and versatile LED display and lighting technology.

Photons and electrons one on one
The dynamics of electrons changes ever so slightly on each interaction with a photon.

An advance in molecular moviemaking shows how molecules respond to two photons of light
Some of the molecules' responses were surprising and others had been seen before with other techniques, but never in such detail or so directly, without relying on advance knowledge of what they should look like.

The imitation game: Scientists describe and emulate new quantum state of entangled photons
A research team from ITMO University, MIPT and Politecnico di Torino, has predicted a novel type of topological quantum state of two photons.

What if we could teach photons to behave like electrons?
The researchers tricked photons - which are intrinsically non-magnetic - into behaving like charged electrons.

Read More: Photons News and Photons Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.