An external cavity diode laser is constructed and shown to have stable, narrow-linewidth operation around 840 nm. Based on this laser and a photoacoustic detector, a gas monitoring system capable of measuring absorption coefficients as low as 10-8 cm-1 is developed. The continuous (mode-hop-free) tuning range of the laser is found to exceed 100 GHz, which makes possible the spectrally resolved detection of water vapor absorption lines. The photoacoustic cell with the external cavity diode laser as a light source offers great potential for the development of a portable, automated gas detection system.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics