title: Compact, broadly tunable, mid-IR source for the spectroscopic investigation of molecular reference lines in the 27- to 33-THz range.
abstract: We report on the improvement of a tunable, high resolution, diode laser-based, difference-frequency spectrometer using an AgGaS(2) nonlinear crystal. We use a type-II cut crystal as a part of the improvement compared with a type-I cut, which was used in our preliminary setup. The two tunable laser-diodes are operating near lambda(3)=778 nm (pump) and lambda(2)=842 nm (signal) with a sub-100-kHz linewidth. The high resolution spectrometer is being developed as an alternative to CO(2) laser spectrometers in the 9- to Il-mum range. Using a dual-arm cavity to enhance the two radiation powers, and with 35 mW in front of the 778-nm arm and 100 mW in front of the 842 nm arm, about 70 nW of the tunable 10-mum radiation are generated. This power level is enough to investigate the linear absorption spectroscopy of SF(6). Doppler-limited spectra over 2 GHz, are recorded, showing the wide continuous tunability of the spectrometer.
authors.affiliation: Bur. Nat. de Metrol., Obs. de Paris.
authors.forename: T
authors.initials: T
authors.lastname: Kaing
authors.forename: J J
authors.initials: JJ
authors.lastname: Zondy
authors.forename: A
authors.initials: A
authors.lastname: Yelisseyev
authors.forename: S
authors.initials: S
authors.lastname: Lobanov
authors.forename: L
authors.initials: L
authors.lastname: Isaenko