Internally excited acoustic resonator for photoacoustic trace detection.
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.
Danworaphong
Sorasak
S
Department of Physics, Brown University, Providence, Rhode Island 02912, USA.
Calasso
Irio G
IG
Beveridge
Andrew
A
Diebold
Gerald J
GJ
Gmachl
Claire
C
Capasso
Federico
F
Sivco
Deborah L
DL
Cho
A Y
AY