Determination of the coherency matrix of a broadband stochastic electromagnetic light beam

Abstract

The statistical ensemble of a fluctuating, statistically-stationary electromagnetic light beam is presented in terms of a 2 × 2 matrix, so-called coherency matrix. The method to determine such matrix for a quasi-monochromatic light beam has been proposed for many years. In this paper, we demonstrate that the method needs to be only slightly modified to determine the matrix elements of a broadband stochastic electromagnetic light beam, if one uses the representation of statistical wave fields in the space–frequency domain. The implementation of the method is demonstrated, and the coherency matrix measurement is validated using a well-defined elliptically polarized beam.

Keywords:

• coherency matrix
• spectral density matrix
• polarization

Acknowledgements

We would like to thank the Royal Thai Government, the UCF I2lab Foundation, the Florida Photonics Center of Excellence (FPCE), and the U.S. Army Research Office for supporting this work. We thank Florian Fournier for stimulating discussions related to the time-domain coherency matrix measurements.