Single-shot measurement of phase and topological properties of orbital angular momentum radiation through asymmetric lateral coherence

Abstract

We show a single-shot technique to measure topological and phase properties of radiation carrying orbital angular momentum. The single-shot method is effectively described as the one-dimensional case of a more general two-dimensional approach based on scanning interferometry (asymmetric lateral coherence). The validity of the method has been experimentally verified and the applicability to ultrarelativistic sources of hard x-rays has been discussed. The method is suitable to characterize phase and topological properties of x-ray sources by using simple apertures.

Probability of radiation of twisted photons by cold relativistic particle bunches

“…the normalization condition for ρ(b) is reduced to (40). These bunches provide a generalization of axially symmetric bunches for which the radiation of twisted photons was considered in [10].…”

“…The generated twisted photons can be used further in various applications (see, e.g., [11][12][13][14][15][16][36][37][38][39]) or recorded by a specially designed detector of twisted photons. At the present moment, there are elaborated several methods to record twisted photons in the X-ray range [40] and below [41][42][43][44][45]. Thus the knowledge of properties of radiation of twisted photons by bunches of particles can also be employed for development of new methods of diagnostics of the bunch structure (see [2,18,46] for the examples of such techniques).…”

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

“…As far as a homogeneous medium is concerned, the theory of radiation of twisted photons is known in this case (see the description of the Vavilov-Cherenkov process in [16,17]). However, the detectors of twisted photons [18][19][20][21][22][23] or the objects that should be irradiated by them [24][25][26][27] are usually positioned outside of the medium. When the twisted photons escape from the medium, the form of their peculiar phase front can be destructed.…”

Heterodyne Near Field Speckles: from laser light to X-rays

“…By properly scanning an array of double-slits with different spacings, the shear displacement of a reference fringe allows to measure the Laplacian of the phase distribution, namely the wavefront curvature [177]. By further exploiting the peculiar intrinsic curvature properties of vortex beams, the method has recently succeeded in providing a strictly local measurement of the topological charge in single-shot conditions [178][179][180][181][182]. The analogy with the XSS selfcorrelation mode can be made explicit by the correspondence between the double-slit scan with the shear displacement of the reference fringe and the diffuser scan with the shear of the maximum of the cross-correlation function.…”