Optical manipulation using optimal annular vortices

Abstract

We discuss a simple method to generate a configurable annular vortex beam (AVB) with the maximum possible peak intensity, employing a phase hologram whose transmittance is the phase of a Bessel beam. Due to its maximum intensity, the AVB provides the optimal density of the orbital angular moment. Another attribute of the generated AVB is the relatively high invariance of the intensity profile when the topological charge is changed. We demonstrate the advantages and flexibility of these AVBs for optical trapping applications.

High-order orbital angular momentum mode generator based on twisted photonic crystal fiber

“…The secret of the successful observation of high-order modes is that leaky orbital resonances in the twisted PCF cladding have a high coupling efficiency of more than −20 dB. © 2018 Optical Society of America The optical orbital angular momentum (OAM) of a light beam has exhibited potential applications in optical communications [1], optical tweezers [2], and atom manipulation [3]. Existing ways to generate OAM modes are usually based on free-space coupling methods, such as cylindrical-lens mode converters [4], spatial light modulators [5], integrated silicon devices [6], and micrometer-scale metamaterials [7].…”

Generation of Orbital Angular Momentum Modes Using Fiber Systems

“…Takingσ + OAM −l as an example, if simultaneously calculating the equivalent CV modes, we obtain the typical expression similar to that found in almost all the studies, namely, σ + OAM −1 = TM 01 + iTE 01 . Equations (2)- (4) give all of these transformation relations among CV modes, OAM modes and LP modes. As for the detection of OAM beams, researchers have aimed to detect the TC, that is, the helical degree of the OAM beams.…”

“…For the first type, namely the generation of linearly-polarized OAM (LP-OAM) modes, the LP-OAM modes in the x and y polarized directions can be obtained by eliminating other component in the OAM mode bases except one, such as (x −l , y −l , x +l , y +l ) T = (1, 0, 0, 0) T , which corresponds tô xOAM −l , an x-linear polarized OAM beam with TC = +l. The expression in other mode bases can be obtained by substituting this vector into Equation (2) or Equation (4). (x −l , y −l , x +l , y +l ) T = (1, 0, 0, 0) T is equivalent as (A, B, C, D) T = 0.5, 0.5i, 0.5, −0.5i T and (x e , y e , x o , y o ) T = (1, 0, −i, 0) T .…”

“…OAM beams with different TC can be regarded as several independent dimensions carrying information. These properties make OAM beams different from conventional plane light waves and many unique applications in terms of atom manipulation [2][3][4], nanoscale microscopy [5], optical tweezers [6][7][8], optical communication [9][10][11][12][13], and data storage [14,15] have been realized.…”

Controllable all-fiber generation/conversion of circularly polarized orbital angular momentum beams using long period fiber gratings

“…As one of the most fundamental physical quantities in classical and quantum electrodynamics, orbital angular momentum (OAM) of light has initiated widespread interest in many areas, including optical tweezers [1], atom manipulation [2][3][4], nanoscale microscopy [5], quantum information processing, and large-capacity optical communication [6][7][8]. A beam of light carrying OAM possesses a phase φ(l,ϕ) = exp(ilϕ) in the transverse plane, where ϕ is the azimuth angle and l is the topological charge number.…”