Continuously tunable orbital angular momentum generation controlled by input linear polarization

Abstract

In this Letter, we theoretically and experimentally demonstrate a new method to generate tunable orbital angular momentum (OAM) by continuously changing the angle of linear polarization of the input light. We use the Fourier series of left- and right-hand projections to prove that the average OAM smoothly varied from l=-1 to l=1 with the angle of LP of input light changing from 0 to π, which is fulfilled by an electrical polarization controller.

Generation of Orbital Angular Momentum Modes Using Fiber Systems

“…The mode couple module is used to couple the fundamental mode to a specific lth-order CV mode. It is usually composed of the fiber gratings [31][32][33][34][35][36][37][38][39][40][41][42][43][44] and the fiber couplers [45][46][47][48]. As mentioned above, the lth-order CV modes are composed of four degenerated modes.…”

“…Compared with spatial generating methods, fiber generating methods have shown their certain advantages. A converter applied in fiber methods can be fiber gratings [31][32][33][34][35][36][37][38][39][40][41][42][43][44], mode selective couplers [45][46][47][48], and microstructure optical fibers [49][50][51] and photonic lanterns [52,53]. As a cylindrical waveguide, fiber is a natural beam shaper for OAM beams.…”

On-demand multiplexed vortex beams for terahertz polarization detection based on metasurfaces

“…Scalar vortex beams are the solutions of the scalar wave equation under paraxial approximation, and the phase uncertainty property at their center leads to doughnut-shaped intensity distributions. [27][28][29] The vortex beam determined by the spatial spiral phase wavefront structure can carry the orbital angular momentum (OAM), and the spiral phase profile can be described as exp(ilθ), which carries OAM of lħ per photon. 30 The parameters l and θ denote the topological charge and the azimuth angle, respectively.…”

Helical Long Period Fiber Grating Inscribed in Elliptical Core Polarization-Maintaining Fiber

“…Helical long period fiber gratings (HLPFGs) with periodic screw-type refractive index (RI) modulation along the fiber axis in single mode fiber (SMF) [1][2][3], few mode fiber (FMF) [4,5], multi-core fiber [6], photonic crystal fiber (PCF) [7][8][9][10], photonic band-gap fiber (PBF) [11], and polarization-maintaining fiber (PMF) [12] have been fabricated and demonstrated by using the CO 2 laser irradiation, electric arc discharge, and hydrogen-oxygen flame heating technique. These HLPFGs in different types of fibers have been widely used as orbital angular momentum (OAM) mode generator, filter [13,14], and fiber sensor [15][16][17].…”