Open AccessModulation of spectral intensity, polarization and coherence of a stochastic electromagnetic beam
Author(s) -
Guannan Wu,
Yangjian Cai
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.008700
Subject(s) - optics , physics , m squared , degree of coherence , degree of polarization , radial polarization , coherence (philosophical gambling strategy) , laser beam quality , polarization (electrochemistry) , gaussian beam , beam diameter , beam (structure) , coherence theory , coherence time , beam divergence , radiant intensity , coherence length , scattering , radiation , laser , laser beams , chemistry , superconductivity , quantum mechanics
Analytical formula for the cross-spectral density matrix of a stochastic electromagnetic Gaussian Schell-model (EGSM) beam truncated by a circular phase aperture propagating in free space is derived with the help of a tensor method, which provides a reliable and fast way for studying the propagation and transformation of a truncated EGSM beam. Statistics properties, such as the spectral intensity, the degree of coherence, the degree of polarization and the polarization ellipse of a truncated EGSM beam in free space are studied numerically. The propagation factor of a truncated EGSM beam is also analyzed. Our numerical results show that we can modulate the spectral intensity, the polarization, the coherence and the propagation factor of an EGSM beam by a circular phase aperture. It is found that the phase aperture can be used to shape the beam profile of an EGSM beam and generate electromagnetic partially coherent dark hollow or flat-topped beam, which is useful in some applications, such as optical trapping, material processing, free-space optical communications.