Abstract

The source of errors in depolarization measurements using laser excitation and their dependence on monochromator, image magnification, and cell geometry is considered. Two common ways of measuring these ratios are considered, and the extent of the expected divergence errors in capillary cells is calculated for the 90° scattering geometry. It is shown that the ratio ρ_<i>n</i> determined by rotating the laser polarization from perpendicular to parallel to the scattering direction is subject to errors which limit its usefulness for highly polarized lines but is acceptable for depolarized lines. Use of an analyzer gives depolarization ratios ρ₃ with the highest accuracy.

Determination of the Depolarization Factors of Highly Polarized Raman Lines*

A. E. Douglas and D. H. Rank
J. Opt. Soc. Am. 38(3) 281-287 (1948)

A Method for Determining Depolarization Factors in Raman Spectra

D. H. Rank, R. J. Pfister, and H. H. Grimm
J. Opt. Soc. Am. 33(1) 31-35 (1943)

Accurate measurements of the Raman scattering coefficient and the depolarization ratio in liquid water

Andrew Bray, Robert Chapman, and Taras Plakhotnik
Appl. Opt. 52(11) 2503-2510 (2013)

Atmospheric Raman depolarization-ratio measurements

Ulla Wandinger, Albert Ansmann, and Claus Weitkamp
Appl. Opt. 33(24) 5671-5673 (1994)

Reexamination of depolarization in lidar measurements

Gary G. Gimmestad
Appl. Opt. 47(21) 3795-3802 (2008)