Polarization-induced spectral changes on propagation of stochastic electromagnetic beams

It was shown some years ago that the spectrum of a stochastic scalar field depends not only on the source spectrum but also on the degree of coherence of the source. In this paper we show that there are electromagnetic fields for which not only the state of coherence of the source, but also its degree of polarization affect the spectrum of the radiated field. We illustrate the analysis by diagrams which show the far-zone spectra of some stochastic electromagnetic beams generated by sources of different states of coherence and different degrees of polarization. The spectra of the radiated field depend both on coherence properties of the source and its degree of polarization and are found to be different in different directions of observation

Spectral anomalies by superposition of polychromatic Gaussian beam and Gaussian vortex beam

We study the spectral property of a composite field superposed by a polychromatic Gaussian beam and a polychromatic Gaussian beam with an embedded mth-order vortex. It is shown that, in the overall spectral shift distribution, there exist m small areas where sharp spectral anomaly takes place, similarly and respectively, which are related with the ratio of the respective amplitudes of the two composite beams and the relative phase between them. Detailed investigation reveals that, for each small area, there exists a "main line", along which spectral switch can be observed

Complex field measurement in a single pixel hybrid correlation holography

We propose a new scheme for recovery of complex valued object in a single-pixel hybrid correlation holography. Idea is to generate an intensity correlation hologram by correlation of the intensity of a single pixel detector and digitally propagated two dimensional intensity patterns. The proposed scheme with theoretical basis is described to reconstruct the objects from a single pixel detector. An experimental arrangement is proposed and as a first step to realize the technique, we have simulated the experimental model for imaging of two different complex objects.Comment: 4 [age

Ghost Diffraction Holography: A Correlation Assisted Quantitative Tool for Complex Field Imaging and Characterization

The fascinating domain of ghost imaging has been a subject of interest in the fundamental and applied research for the last two decades with its promising applications in various imaging and characterization scenarios. In this chapter, we discuss the recently developed ghost diffraction holography (GDH) system with due emphasis on the capability of quantitative complex-field imaging in the ghost framework. The development of the unconventional correlation-assisted GDH technique by adopting the holography concept in ghost diffraction scheme is described, and the quantitative phase imaging capability is demonstrated in the microscopy. In addition, the technique exploits the spatial statistics of time-frozen recorded speckle intensity with snapshot detection in ghost framework, which could broaden the applications of the developed microscopy to real-time imaging of two- and three-dimensional biological samples with high resolution. Furthermore, we discuss demonstrated applications of the technique in the imaging various spatially varying complex-valued macroscopic and microscopic samples and the potential application of the technique in the recovery and characterization of orbital angular momentum modes encoded in spatially incoherent speckle field

Intracavity generated visible self-reconstructing Bessel-like laser beams by thermal effect

Abstract(#br)In this paper we report the intracavity realization of visible reconstructing Bessel-like beams when a thin Nd:YVO 4 crystal is inserted in a diode-pumped Pr:YLF laser at 639.5 nm. The position of the thin crystal and the intracavity power determine the Bessel-like mode generated. The self-reconstructing characteristic of the obtained Bessel-like beam is also demonstrated

Propagation of the degree of cross-polarization of a stochastic electromagnetic beam through the turbulent atmosphere

The behavior of the recently introduced spectral degree of cross-polarization of a stochastic electromagnetic beam-like field on propagation through the turbulent atmosphere is analyzed. Unlike the spectral degree of coherence, the degree of cross-polarization is generally unbounded and does not decrease with propagation distance. We support the analysis by numerical examples relating to two model sources: with uncorrelated and partially correlated mutually orthogonal transverse components of the electric field

Spectral and polarization properties of stochastic electromagnetic beams propagating in gain or absorbing media

Based on the generalized Huygens–Fresnel diffraction principle and on the unified theory of coherence and polarization of light, the analytical expressions for the cross-spectral density matrix of a class of stochastic electromagnetic beams in linear, deterministic media with gain or absorption, in which the wave number is generally complex, has been derived. In particular, through numerical examples based on our analytical formulas the behavior of the spectral density, and of the degree of polarization of the Electromagnetic Gaussian Schell-model is analyzed. It is demonstrated how these statistical properties of the beam propagating in such media depend on the properties of the source and on the wave number of the medium. Numerical examples relate to two model sources: with uncorrelated and partially correlated mutually orthogonal transverse components of the electric field. The results will impact potential applications involving natural absorbing media, such as oceanic waters, and man-made media such as active lasers, for instance

Invariance And Non-Invariance Of The Spectra Of Stochastic Electromagnetic Beams On Propagation

A generalization from random scalar fields to random electromagnetic fields is obtained, of the phenomenon of correlation-induced spectral changes generating, for example, spectral shifts. An electromagnetic version of the scaling law is also obtained. © 2006 Optical Society of America