Faraday rotation spectroscopy (FRS) of O2 is performed at atmospheric conditions using a DFB diode laser and permanent rare-earth magnets. Polarization rotation is detected with a hybrid-FRS detection method that combines the advantages of two conventional approaches: balanced optical-detection and conventional FRS with an optimized analyzer offset angle for maximum sensitivity enhancement. A measurement precision of 0.6 ppmv·Hz-1/2 for atmospheric O2 has been achieved. The theoretical model of hybrid detection is described, and the calculated detection limits are in excellent agreement with experimental values.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics