Degree of polarization of a spectral electromagnetic Gaussian Schell-model beam passing through 2-f and 4-f lens systems

Spectral electromagnetic Gaussian Schell-model (SEGSM) beam is a generalization of Gaussian Schell model beam having parameters with spectral dependence, which offers a basic classical model for random electromagnetic wide-sense statistically stationary beam-like fields. We study degree of polarization (DOP) of a SEGSM beam passing through 2-f and 4-f lens systems. It is observed that for a 2-f lens system, the spectral DOP at the back focal plane of the lens changes with respect to the transverse position from the optic axis, and the spectral parameters of the beam. For a 4-f lens system, the spectral DOP at the back focal plane is independent of the transverse position of the beam, whereas it depends on the beam parameters such as mean value of rms beam-width, rms width of correlation function, and size of aperture placed at the Fourier plane of the lens system.