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.”
* 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.
Mark Esser | EurekAlert!
Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles
Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Life Sciences
22.08.2017 | Life Sciences
22.08.2017 | Life Sciences