ABSTRACT
The phenomenon of the correlation-induced spectral changes (CISC) in the spectral density of a wide-stationary light beam is shown to occur for each component in its single-radius coherence-OAM (COAM) matrix, with the magnitude quantitatively depending on the OAM indices. As the diagonal elements of the COAM matrix are also radially resolved OAM spectrum components, the new effect may be viewed as the CISC in the OAM spectrum. Using the Gaussian Schell-model beam with the Gaussian spectral line, we then demonstrate the spectral shifts appearing on propagation in vacuum in its radially resolved OAM spectrum. We also prove the spectral invariance of the spatially integrated OAM spectrum.
ABSTRACT
We establish the properties of the cross-spectral density orbital angular momentum (CSD-OAM) matrix of a stationary optical beam-like field and use them to introduce the OAM-resolved polarization properties. It is shown that sufficiently general random fields contain two types of polarization, one relating to a single OAM mode and the other to a pair of modes.
ABSTRACT
Matrices characterizing the orbital angular momentum (OAM) transformations of deterministic and random light beams by commonly used OAM-modulating optical systems are revealed. Such matrices are the counterparts of the Jones and the Mueller matrices in polarization optics defined for the input and output OAM indices and the radial variables. In particular, matrices of systems leading to OAM mode shift, dispersion, and coupling are discussed.
ABSTRACT
We establish a general framework for introducing novel, to the best of our knowledge, classes of beams possessing precisely tailored coherence-orbital angular momentum (COAM) matrices, with the help of Bochner's theorem. The theory is illustrated by several examples relating to COAM matrices having a finite and infinite number of elements.
