Transverse mode multiplexing using the helical eigen-beams of orbital angular momentum

Characteristics of Spiral Patterns Formed by Coaxial Interference between Two Vortex Beams with Different Radii of Wavefront Curvatures

“…The Laguerre-Gaussian (LG) vortex beam with an exp(ilϕ) azimuthal phase, where l is called topological charge (TC), has a doughnut intensity distribution and carries an orbital angular momentum (OAM) of lh (h is the reduced Planck's constant) per photon [1]. It is widely applied in realms such as optical communications [2][3][4], trapping, and manipulating micrometer-sized particles [5,6], measuring the rotational speed of a rotating object [7], fabricating chiral nanostructures [8][9][10], and atomic optics and spectroscopy [11], etc. The phase structure of a vortex beam presents l intertwined helical phase fronts.…”

Are optical vortices robust in twisted fibres?

“…The past few years of the development of singular optics [1] have unveiled the extreme relevance of optical vortices (OVs) [2] to the problem of increasing the 'information capacity' of a signal. In a vast body of research it has been established that using OVs as information carriers could essentially increase the amount of information which can be encoded in a photon [3][4][5][6][7][8]. Basically, this property of OVs is closely related to the fact that OVs are eigenstates of orbital angular momentum (OAM) operators, and states with intrinsic OAM possess an additional degree of freedom.…”

Angular momentum of low frequency electromagnetic fields

“…Recently, the orbital angular momentum became of interest for data transmission, because the number of channels in a fiber could be increased considerably [11]. The same holds in the RF-region [12].…”