Photoacoustic-based detector for infrared laser spectroscopy

Journal Article · Mon Jul 25 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4959886· OSTI ID:22594433

Scholz, L.

In this contribution, we present an alternative detector technology for use in direct absorption spectroscopy setups. Instead of a semiconductor based detector, we use the photoacoustic effect to gauge the light intensity. To this end, the target gas species is hermetically sealed under excess pressure inside a miniature cell along with a MEMS microphone. Optical access to the cell is provided by a quartz window. The approach is particularly suitable for tunable diode laser spectroscopy in the mid-infrared range, where numerous molecules exhibit large absorption cross sections. Moreover, a frequency standard is integrated into the method since the number density and pressure inside the cell are constant. We demonstrate that the information extracted by our method is at least equivalent to that achieved using a semiconductor-based photon detector. As exemplary and highly relevant target gas, we have performed direct spectroscopy of methane at the R3-line of the 2v{sub 3} band at 6046.95 cm{sup −1} using both detector technologies in parallel. The results may be transferred to other infrared-active transitions without loss of generality.

• OSTI ID: 22594433
• Journal Information: Applied Physics Letters, Vol. 109, Issue 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABSORPTION SPECTROSCOPY
CROSS SECTIONS
DENSITY
INFRARED SPECTROMETERS
LASER SPECTROSCOPY
LASERS
MEMS
METHANE
MOLECULES
PHOTOACOUSTIC EFFECT
PHOTOACOUSTIC SPECTROSCOPY
PHOTONS
QUARTZ
SEMICONDUCTOR MATERIALS