Open AccessHybrid Faraday rotation spectrometer for sub-ppm detection of atmospheric O_2
Author(s) -
Eric Zhang,
Brian E. Brumfield,
Gerard Wysocki
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.015957
Subject(s) - faraday effect , optics , spectrometer , polarization (electrochemistry) , offset (computer science) , faraday rotator , spectrum analyzer , optical isolator , laser , spectroscopy , sensitivity (control systems) , polarimetry , rotation (mathematics) , materials science , physics , remote sensing , magnetic field , scattering , chemistry , quantum mechanics , geology , computer science , programming language , geometry , mathematics , electronic engineering , engineering
Faraday rotation spectroscopy (FRS) of O(2) 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 O(2) has been achieved. The theoretical model of hybrid detection is described, and the calculated detection limits are in excellent agreement with experimental values.