title: Longwave infrared, single-frequency, tunable, pulsed optical parametric oscillator based on orientation-patterned GaAs for gas sensing.
abstract: We demonstrate a nanosecond single-frequency nested cavity optical parametric oscillator (NesCOPO) based on orientation-patterned GaAs (OP-GaAs). Its low threshold energy of 10 μJ enables to pump it with a pulsed single-frequency Tm:YAP microlaser. Stable single-longitudinal-mode emission is obtained owing to Vernier spectral filtering provided by the dual-cavity doubly-resonant NesCOPO scheme. Crystal temperature tuning covers the 10.3-10.9 μm range with a quasi-phase-matching period of 72.6 μm. A first step toward the implementation of this device in a differential absorption lidar is demonstrated by carrying out short-range standoff detection of ammonia vapor around 10.4 μm. Owing to the single-frequency emission, interferences due to absorption by atmospheric water vapor can be discriminated from the analyte signal.
authors.forename: Q
authors.initials: Q
authors.lastname: Clément
authors.forename: J-M
authors.initials: JM
authors.lastname: Melkonian
authors.forename: J-B
authors.initials: JB
authors.lastname: Dherbecourt
authors.forename: M
authors.initials: M
authors.lastname: Raybaut
authors.forename: A
authors.initials: A
authors.lastname: Grisard
authors.forename: E
authors.initials: E
authors.lastname: Lallier
authors.forename: B
authors.initials: B
authors.lastname: Gérard
authors.forename: B
authors.initials: B
authors.lastname: Faure
authors.forename: G
authors.initials: G
authors.lastname: Souhaité
authors.forename: A
authors.initials: A
authors.lastname: Godard