A uniaxial gas model of the geometrical dependence of polarization spectroscopy

Abstract

A uniaxial gas model of polarization spectroscopy signal strength has been developed. Based on this model, theoretical expressions have been derived both for linear and circular polarization cases. The theoretical expressions developed predict that non-zero signal strength may be obtained, for both linearly and circularly polarized pump beams, at the normal intersection of the pump and probe beams. This prediction is particularly useful when polarization spectroscopy is used in imaging applications. The developed expressions have successfully been applied to explain the first orthogonal planar laser polarization spectroscopy imaging of OH radicals in a pre-mixed CH4/O2 flame, for both linearly and circularly polarized pump beams