Degree Of Cross-polarization Research Articles

Experimental investigation of degree of cross-polarization for an electromagnetic Gaussian-Schell model beam.

We investigate the properties of the degree of cross-polarization (DOCP) for an electromagnetic Gaussian-Schell model (EMGSM) beam in the radial direction of the cross section of the beam. The coherence and polarization features of a partially coherent light beam are engineered to construct the isotropic and non-isotropic EMGSM beams, and the resulting changes in the DOCP are examined. For experimental realization, a double-slit interferometer is utilized at the output to probe the coherence properties for different polarization components across the beam diameter of an electromagnetic source. Experimental observations infer that variation in DOCP does not become apparent for isotropic coherence widths in the orthogonal polarization directions, whereas the variation can be apparent only once both the coherence widths are distinct. Furthermore, experimentally, a special case is also investigated for which the value of DOCP goes beyond unity. The DOCP finds application in areas such as second-order intensity interference, imaging, and characterization of non-homogeneously polarized beams.

Correlation between intensity fluctuations and degree of cross-polarization of light waves on scattering

Correlation between intensity fluctuations (CIF) in the three-dimensional scattered field has been deduced, only provided that the fluctuating electric field obeys Gaussian statistics. This discussion results in the introduction of a new definition of the degree of cross-polarization (DCP) which depends on two locations and can reduce to the classical degree of polarization as its two locations coinciding. The concept of DCP in the general three-dimensional scattered field is considered to be especially useful, for instance, in inverse problems of scattering.

Hanbury Brown–Twiss effect with electromagnetic waves

The classic Hanbury Brown-Twiss experiment is analyzed in the space-frequency domain by taking into account the vectorial nature of the radiation. We show that as in scalar theory, the degree of electromagnetic coherence fully characterizes the fluctuations of the photoelectron currents when a random vector field with Gaussian statistics is incident onto the detectors. Interpretation of this result in terms of the modulations of optical intensity and polarization state in two-beam interference is discussed. We demonstrate that the degree of cross-polarization may generally diverge. We also evaluate the effects of the state of polarization on the correlations of intensity fluctuations in various circumstances.

Polarization and intensity correlations in stochastic electromagnetic beams upon interaction with devices of polarization optics

Based on the recently formulated unified theory of coherence and polarization of light, we explore the behavior of the intensity–intensity correlations and the auxiliary quantity called the degree of cross-polarization in stochastic electromagnetic beams upon their passage through the devices of polarization optics. In particular, the effects of deterministic devices (such as polarizers, absorbers, compensators, and rotators) as well as of random devices (such as spatial light modulators) on passing beams are investigated. Our results may find applications in polarimetric communications, imaging and sensing.

Correlation properties of random electromagnetic beams in laser resonators

With the help of the generalized Huygens–Fresnel principle and the tensor approach for electromagnetic stochastic beams we investigate the behavior of their two-point spatial correlation properties on interaction with a laser resonator. In particular, the evolution of the degree of coherence, of the degree of cross-polarization and of the intensity correlations (at one and two points in space) is analyzed for typical beams and cavities. The theory is illustrated by numerical curves pertaining to various correlation properties of typical electromagnetic Gaussian Schell-model beams.

Propagation properties of partially coherent radially polarized beam in a turbulent atmosphere

Based on the Huygens–Fresnel principle and the unified theory of coherence and polarization of partially coherent beams, we investigate the propagation characteristics of a partially coherent radially polarized doughnut (PCRPD) beam in a turbulent atmosphere. It is found that, after propagating through a turbulent atmosphere, the doughnut beam spot is changed into a circular Gaussian beam. Moreover, the degree of coherence, the degree of polarization and the degree of cross-polarization of the beam will change on propagation, and this change is dependent upon the degree of coherence of the source and atmospheric turbulence.

Intensity fluctuations and the degree of cross-polarization in stochastic electromagnetic beams

An expression is derived for the correlation between intensity fluctuations at pairs of points in a stochastic electromagnetic beam, obeying Gaussian statistics. The new formula, which is of particular interest for the theory of the Hanbury Brown?Twiss effect, applies to beams of any state of coherence and state of polarization. It contains a new 'two-point' degree of polarization whose presence indicates that, in general, the knowledge of the degree of coherence and of the usual degree of polarization are not adequate for determining the correlation between intensity fluctuations.