Compact and tunable mid-infrared laser using QPM-LN waveguide and TLA

摘要

A compact and tunable difference frequency generation mid-infrared laser for gas sensing is developed using a quasi-phasc-matched L.iNbO_3 (QPM-LN) waveguide and a tunable laser diode array (TLA). The absorption spectra of methane from the -third- to + fifth-order aroand 3.3 μm are observed by Tuning the QPM-LN wqveguide temperaiure rnand the TLA wavelength. The absorption line width is investigated with nigh spectral resolution seanning and the result is compared with that calculated from the HITRAN database.