title: Internally excited acoustic resonator for photoacoustic trace detection.
abstract: The quantum-cascade laser can be used as an infrared source for a small portable photoacoustic trace gas detector. The device that we describe uses a quantum-cascade laser without collimating optics mounted inside an acoustic resonator. The laser is positioned in the center of a longitudinal resonator at a pressure antinode and emits radiation along the length of the resonator exciting an axially symmetric longitudinal acoustic mode of an open-ended cylindrical resonator. Experiments are reported with an 8-microm, quasi-cw-modulated, room-temperature laser used to detect N2O.
authors.affiliation: Department of Physics, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: Sorasak
authors.initials: S
authors.lastname: Danworaphong
authors.forename: Irio G
authors.initials: IG
authors.lastname: Calasso
authors.forename: Andrew
authors.initials: A
authors.lastname: Beveridge
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Diebold
authors.forename: Claire
authors.initials: C
authors.lastname: Gmachl
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Sivco
authors.forename: A Y
authors.initials: AY
authors.lastname: Cho