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-μm, quasi-cw-modulated, room-temperature laser used to detect N2O.
All Science Journal Classification (ASJC) codes
- Engineering (miscellaneous)
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering