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 | Newswise Science News
Did you know that the wrapping of Easter eggs benefits from specialty light sources?
13.04.2017 | Heraeus Noblelight GmbH
To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
05.04.2017 | Carnegie Institution for Science
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy