Noise equalization in Stokes parameter images obtained by use of variable-retardance polarimeters
Abstract
An imaging variable retardance polarimeter was developed and tested by Tyo and Turner [Proc. SPIE 3753,
214 (1999)]. The signal-to-noise ratio (SNR) in the reconstructed polarization images obtained with this
system varied for the four Stokes parameters. The difference in SNR is determined to be due to differences
in the Euclidean lengths of the rows of the synthesis matrix used to reconstruct the Stokes parameters from
the measured intensity data. I equalize (and minimize) the lengths of the rows of this matrix by minimizing
the condition number of the synthesis matrix, thereby maximizing the relative importance of each of the
polarimeter measurements. The performance of the optimized system is demonstrated with simulated data,
and the SNR is shown to increase from a worst case of 23.1 dB for the original settings to a worst case of
15.0 dB for the optimized system.
Description
Optics Letters, Volume 25, No. 16, pp. 1198-1200 (August 15, 2000)