Sequence of focused optical vortices generated by a spiral fractal zone plate

Abstract

We propose a method for producing a sequence of focused optical vortices along the propagation direction by using a spiral fractal zone plate. The generated beam possesses the optical vortices embedded at subsidiary foci as well as the major ones of the fractal zone plate. The experimental results are obtained in good agreement with the simulations.

Devil’s vortex-lenses

“…A new type of vortex lenses, coined "devil's vortex-lenses", has been introduced. To avoid the losses that characterize the spiral fractal zone plates [5] and to improve their diffraction efficiency, the phase function for a typical devil's vortex lens has a fractal blazed profile. It is well known that continuous phase profiles generally also have a better performance as measured by the intensity uniformity.…”

Devil’s vortex-lenses

“…A new type of vortex lenses, coined "devil's vortex-lenses", has been introduced. To avoid the losses that characterize the spiral fractal zone plates [5] and to improve their diffraction efficiency, the phase function for a typical devil's vortex lens has a fractal blazed profile. It is well known that continuous phase profiles generally also have a better performance as measured by the intensity uniformity.…”

Synthesis of fractal light pulses by quasi-direct space-to-time pulse shaping

“…This fact is supported by the introduction of a novel family of diffracting apertures known as fractal zone plates (FZPs) [13]. These apertures, among other applications, have been used in the generation of optical vortices employed for trapping and rotating microparticles [14,15] or as image-forming devices with an extended depth of field and reduced chromatic aberration under white-light illumination [16]. FZPs can be regarded as a set of circularly symmetric apertures with spatial self-similar distribution in the squared radial coordinate r 2 .…”

Composite Spiral Zone Plate

“…Furthermore, the two focused vortices of the CSZP have the roughly identical intensity. We also checked the phase singularities of the beam reconstructed by the CSZP with the interferometric measurement method [23]. The interference of the reconstructed beams with a reference beam in the focal regions was implemented.…”

Devil’s vortex-lenses

“…A new type of vortex lenses, coined "devil's vortex-lenses", has been introduced. To avoid the losses that characterize the spiral fractal zone plates [5] and to improve their diffraction efficiency, the phase function for a typical devil's vortex lens has a fractal blazed profile. It is well known that continuous phase profiles generally also have a better performance as measured by the intensity uniformity.…”

Synthesis of fractal light pulses by quasi-direct space-to-time pulse shaping

“…This fact is supported by the introduction of a novel family of diffracting apertures known as fractal zone plates (FZPs) [13]. These apertures, among other applications, have been used in the generation of optical vortices employed for trapping and rotating microparticles [14,15] or as image-forming devices with an extended depth of field and reduced chromatic aberration under white-light illumination [16]. FZPs can be regarded as a set of circularly symmetric apertures with spatial self-similar distribution in the squared radial coordinate r 2 .…”

Composite Spiral Zone Plate

“…Furthermore, the two focused vortices of the CSZP have the roughly identical intensity. We also checked the phase singularities of the beam reconstructed by the CSZP with the interferometric measurement method [23]. The interference of the reconstructed beams with a reference beam in the focal regions was implemented.…”

Devil’s vortex-lenses

“…A new type of vortex lenses, coined "devil's vortex-lenses", has been introduced. To avoid the losses that characterize the spiral fractal zone plates [5] and to improve their diffraction efficiency, the phase function for a typical devil's vortex lens has a fractal blazed profile. It is well known that continuous phase profiles generally also have a better performance as measured by the intensity uniformity.…”

Synthesis of fractal light pulses by quasi-direct space-to-time pulse shaping

“…This fact is supported by the introduction of a novel family of diffracting apertures known as fractal zone plates (FZPs) [13]. These apertures, among other applications, have been used in the generation of optical vortices employed for trapping and rotating microparticles [14,15] or as image-forming devices with an extended depth of field and reduced chromatic aberration under white-light illumination [16]. FZPs can be regarded as a set of circularly symmetric apertures with spatial self-similar distribution in the squared radial coordinate r 2 .…”

Composite Spiral Zone Plate

“…Furthermore, the two focused vortices of the CSZP have the roughly identical intensity. We also checked the phase singularities of the beam reconstructed by the CSZP with the interferometric measurement method [23]. The interference of the reconstructed beams with a reference beam in the focal regions was implemented.…”