We report on the characterization of a novel pulsed mid-IR laser source with respect to its excellent suitability for spectroscopic applications. The compact hybrid laser employs a tunable cw external-cavity diode laser (795 - 825 nm) and a pulsed diode-pumped Nd:YAG laser (1064 nm). This approach of difference-frequency mixing a cw and a pulsed laser in LiNbO3 combines broadband phase-matching, high spectral purity (155 MHz) and broad, continuous tunability (3.16-3.67µm) with a high output (peak) power and signal-to-noise ratio. By quasi-phase-matching in periodically poled LiNbO3, a 20 to 90 times higher conversion efficiency has been achieved compared to birefringent phase-matching, however, at the expense of wavelength tuning performance.

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