Mid-infrared ethene detection using difference frequency generation in a quasi-phase-matched LiNbO3 waveguide

Roberto Grilli, Luca Ciaffoni, Gus Hancock, Robert Peverall, Grant A. D. Ritchie, Andrew J. Orr-Ewing

Research output: Contribution to journalArticle (Academic Journal)peer-review


A periodically poled LiNbO3 (PPLN) crystal waveguide has been used to produce up to 200 mu W of mid-infrared light around 3081 cm(-1) with a wide tunability range of similar to 35 cm(-1). Two commercial near-infrared diode lasers at 1.064 mu m (pump) and 1.583 mu m (signal) are mixed in a nonlinear optical crystal to achieve difference frequency generation. The 48 mm long directly-bonded quasi-phase-matched (QPM) PPLN waveguide shows a conversion efficiency of 12.3% W-1. Applications in trace gas detection have been demonstrated for ethene, using multipass absorption coupled with wavelength modulation spectroscopy, and cavity enhanced absorption spectroscopy with a lock-in detection scheme: bandwidth reduced sensitivities of alpha(min) 8 x 10(-9) and 1.6 x 10(-8) cm(-1) Hz(-1/2)(2 sigma), respectively, have been achieved. (C) 2009 Optical Society of America

Original languageEnglish
Pages (from-to)5696-5703
Number of pages8
JournalApplied Optics
Issue number30
Publication statusPublished - 20 Oct 2009

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