Simple technique for generating the perfect optical vortex

Abstract

We propose an improved technique for generating the perfect optical vortex. This technique is notable for the simplicity of its practical realization and high quality of the results. The efficiency of the proposed technique is illustrated with the results of physical experiments and an example of its application in optical trapping of small particles.

Optimal focusing of a beam in a ring vortex

“…Our discussion and results are connected with previous works dealing with the so called perfect vortex [13][14][15][16], which is an infinitely narrow RV with arbitrary integer topological charge. It is clear that this ideal field cannot be generated in practice.…”

“…As occurs in conventional focusing, the generation of an infinitely narrow RV [13][14][15][16] is impossible. Therefore, it is important to establish the optimal approximation to this field that can be physically implemented.…”

Efficient generation of a perfect optical vortex by using a phase optical element

“…In [3], a narrow ring is imaged by using a 4f-setup, but this way does not allow generation of a POV in the focus of a high-aperture objective for optical manipulation. In [4], instead of the axicon, an amplitude-phase optical element approximating the Bessel mode is proposed. The element in [4] is closest to the optimal phase filter proposed in our work.…”

“…In [4], instead of the axicon, an amplitude-phase optical element approximating the Bessel mode is proposed. The element in [4] is closest to the optimal phase filter proposed in our work. Generation of POV is compared by using 1) an amplitude-phase light field described by a Bessel mode of limited radius, 2) by an optimal phase light field, described in [5] and 3) by the phase field generated by using a conical axicon and SPP [2].…”

Square lattices of quasi-perfect optical vortices generated by two-dimensional encoding continuous-phase gratings

“…As early as 2001, Arlt et al [7] presented a type of vortices whose outer ring-diameter is independent of the charge while the ring-width decreases with the charge. Around two years ago, Ostrovsky and coworkers [8,9] first proposed a complex method for the implementation of a type of "perfect" optical vortices, whose average ring-diameter (defined as the arithmetic average of the inner and outer ring-diameters) and ring-width are both independent of the charge. The implementation is based on a programmable spatial light modulator (SLM).…”