3.5-mu m high-resolution gas sensing employing a LiNbO3 QPM-DFG waveguide module

Journal article

Diode laser technology coupled with a wavelength-conversion unit to produce mid-infrared narrow bandwidth laser light applicable to trace-gas detection and with the potential for high-resolution spectroscopy is described. Quasi-phase-matched difference-frequency generation (QPM-DFG) in a compact and fibre-coupled periodically poled lithium niobate (PPLN) waveguide module mixing 1063 and 1525-nm radiations has been adopted for generating 34 μW of 3.5-μm wavelength laser light. Optical detection methods, including sensitive wavelength modulation spectroscopy and a rapid wavelength chirp technique, have been employed with a single-pass cell to investigate methane and formaldehyde absorption profiles around 2855 cm-1, as proof of principle experiments for high sensitivity and resolution spectroscopy on atmospherically important molecules. © 2008 Springer-Verlag.

Authors: Ciaffoni, L; Grilli, R; Hancock, G; Orr-Ewing, A; Peverall, R

• Publication status: Published
• Journal: APPLIED PHYSICS B-LASERS AND OPTICS
• Volume: 94
• Issue: 3
• Pages: 517-525
• Publication date: 2009-03-01
• DOI: 10.1007/s00340-008-3291-0
• EISSN: 1432-0649
• ISSN: 0946-2171
• Language: English