Improved spectrometer based on nonlinear optics

November 12, 2008

Scientists at Stanford University and Japan's National Institute of Informatics have created a new highly sensitive infrared spectrometer. The device converts light from the infrared part of the spectrum to the visible part, where the availability of superior optical detectors results in strongly improved sensing capabilities.

The research will appear in the Nov. 24 issue of Optics Express, the Optical Society's open access journal. The new spectrometer is 100 times more sensitive than current commercial optical spectrum analyzers used in industrial applications such as optical communication, semiconductor microelectronics and forensic analysis.

Current spectrometers being used on the market today cover a wide spectral range, allow for moderately fast wavelength sweeps, have a good spectral resolution and don't require cryogenic cooling. However, the sensitivity of these instruments is limited, making them unsuitable for capturing single-photon-level spectra at telecommunication wavelengths.

Cryogenic cooling can increase the sensitivity of these devices, yet reduces the usefulness for industrial applications. One possible solution is to up-convert near-infrared to visible light in a nonlinear medium. The up-converted photons can then be detected using a single-photon detector for visible light.

The authors use a single-photon counting module, which results in 100 times better sensitivity. They implemented the frequency conversion via sum-frequency generation in a periodically poled lithium niobate waveguide, which can be thought of as combining two low-energy photons to get one high-energy photon.

Key Findings

-- The up-conversion based spectrometer's sensitivity is 100 times higher compared to current commercial optical spectrum analyzers.

-- Cryogenic cooling is not required for increased sensitivity, making the device practical for a variety of industrial applications.

-- The cost and system complexity of the spectrometer is reduced because it only uses one single-photon detector instead of an array of detectors.

Citation: "Waveguide-Based Single-Pixel Up-Conversion Infrared Spectrometer," Optics Express, Vol. 16, Issue 24.

Source: Optical Society of America

Explore further: Wireless handheld spectrometer transmits data to smartphone

Related Stories

Wireless handheld spectrometer transmits data to smartphone

November 8, 2017

Spectral images, which contain more color information than is obtainable with a typical camera, reveal characteristics of tissue and other biological samples that can't be seen by the naked eye. A new smartphone-compatible ...

The road to ultrahigh-resolution X-ray spectrometers

November 29, 2011

Two recent developments at the Advanced Photon Source explore paths to routine use of sub-meV x-rays to probe low-energy excitations in matter. The first is a remarkable experimental demonstration of an x-ray optical scheme ...

Recommended for you

Brittle starfish shows how to make tough ceramics

December 8, 2017

An international team lead by researchers at Technion-Israel Institute of Technology, together with colleagues from the European Synchrotron, Grenoble, France, have discovered how an echinoderm called Ophiocoma wendtii, known ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.