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 new spectrometer is 100 times more sensitive than current commercial optical spectrum analyzers used in industrial applications such as optical communication and forensic analysis.
The scientists 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. Cryogenic cooling is not required for increased sensitivity, and the cost and system complexity of the spectrometer is reduced because it only uses one single-photon detector instead of an array of detectors.