High sensitivity and high-resolution trace gas detection by means of a mW-power DFG spectrometer around 3.2 µm
Authors: Maddaloni P., Gagliardi G., Malara P., De Natale P.
Autors Affiliation: Istituto Nazionale di Ottica Applicata, Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
Abstract: We report the realization of a mid-infrared tunable coherent radiation source based on difference-frequency generation with an output power that achieves, for the first time, a few mW. The signal and pump beams coming from two widely tunable, cw high power rare-earth-doped amplifiers are mixed into a periodically poled LiNbO3 crystal to produce radiation in the 2.9-3.5 µm spectral interval. The low intensity noise and the good spatial profile of the idler beam are first verified. The suitability of this new spectrometer for high-sensitivity and high-resolution gas detection is then demonstrated by performing saturated absorption spectroscopy of methane. Finally, the future development of a portable, multicomponent gas sensor for environmental monitoring is discussed.
KeyWords: Absorption spectroscopy; Air pollution; Air quality; Bandwidth; Electric frequency control; Fiber optics; Greenhouse effect; Infrared spectrometers; Optical collimators; Photovoltaic cells; Polarization, Difference frequency generation (DFG); Electronic bandwidth; Laser sources; Pump beams; Saturated absorption spectroscopy; Trace analysisDOI: 10.1117/12.559550Connecting to view paper tab on IsiWeb: Click here