Focus shaping using cylindrical vector beams
TL;DR: A focus shaping technique using generalized cylindrical vector beams that can be tailored by appropriately adjusting the rotation angle to obtain peak-centered, donut and flattop focal shapes is reported.
Abstract: We report a focus shaping technique using generalized cylindrical vector beams. A generalized cylindrical vector beam can be decomposed into radially polarized and azimuthally polarized components. Such a generalized cylindrical beam can be generated from a radially polarized or an azimuthally polarized light using a two-half-wave-plate polarization rotator. The intensity pattern at the focus can be tailored by appropriately adjusting the rotation angle. Peak-centered, donut and flattop focal shapes can be obtained using this technique.
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TL;DR: An overview of the recent developments in the field of cylindrical vector beams is provided in this paper, where the authors also discuss the potential of using these beams in other fields.
Abstract: An overview of the recent developments in the field of cylindrical vector beams is
provided. As one class of spatially variant polarization, cylindrical vector beams
are the axially symmetric beam solution to the full vector electromagnetic wave
equation. These beams can be generated via different active and passive methods.
Techniques for manipulating these beams while maintaining the polarization symmetry
have also been developed. Their special polarization symmetry gives rise to unique
high-numerical-aperture focusing properties that find important applications in
nanoscale optical imaging and manipulation. The prospects for cylindrical vector
beams and their applications in other fields are also briefly discussed.
2,361 citations
TL;DR: This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques, for a variety of current and emerging applications.
Abstract: Metallic nanostructures now play an important role in many applications. In particular, for the emerging fields of plasmonics and nanophotonics, the ability to engineer metals on nanometric scales allows the development of new devices and the study of exciting physics. This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques. A variety of current and emerging applications are also covered.
496 citations
TL;DR: A computer-generated hologram is introduced onto SLM for performing the beam conversion and optical realization of a variety of polarization configurations confirms the reliability and flexibility of the method.
Abstract: We describe a convenient approach for generating arbitrary vector beams in a 4-f system with a spatial light modulator (SLM) and a common path interferometric arrangement. A computer-generated hologram is introduced onto SLM for performing the beam conversion. Optical realization of a variety of polarization configurations confirms the reliability and flexibility of our method.
439 citations
TL;DR: In this paper, the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge q at its center (q-plate) is described.
Abstract: We describe the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge q at its center (q-plate). The polarization topological structures for different q-plates and different input polarization states have been studied experimentally by measuring the Stokes parameters point-by-point in the beam transverse plane. Furthermore, we used a tuned q=1/2-plate to generate cylindrical vector beams with radial or azimuthal polarizations, with the possibility of switching dynamically between these two cases by simply changing the linear polarization of the input beam.
354 citations
TL;DR: In this article, the fundamental concepts of vector beams, summarise the various approaches to control them in the laboratory, and give a concise overview of the many applications they have spurned.
Abstract: Vector beams, and in particular vector vortex beams, have found many applications in recent times, both as classical fields and as quantum states. While much attention has focused on the creation and detection of scalar optical fields, it is only recently that vector beams have found their place in the modern laboratory. In this review, we outline the fundamental concepts of vector beams, summarise the various approaches to control them in the laboratory, and give a concise overview of the many applications they have spurned.
294 citations
References
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TL;DR: In this article, an investigation of the structure of the electromagnetic field near the focus of an aplanatic system which images a point source is made, and the results are illustrated by diagrams and in a tabulated form based on data obtained by extensive calculations on an electronic computor.
Abstract: An investigation is made of the structure of the electromagnetic field near the focus of an aplanatic system which images a point source. First the case of a linearly polarized incident field is examined and expressions are derived for the electric and magnetic vectors in the image space. Some general consequences of the formulae are then discussed. In particular the symmetry properties of the field with respect to the focal plane are noted and the state of polarization of the image region is investigated. The distribution of the time-averaged electric and magnetic energy densities and of the energy flow (Poynting vector) in the focal plane is studied in detail, and the results are illustrated by diagrams and in a tabulated form based on data obtained by extensive calculations on an electronic computor. The case of an unpolarized field is also investigated. The solution is riot restricted to systems of low aperture, and the computational results cover, in fact, selected values of the angular semi-aperture a on the image side, in the whole range 0 ≤ α ≤ 90°. The limiting case α → 0 is examined in detail and it is shown that the field is then completely characterized by a single, generally complex, scalar function, which turns out to be identical with that of the classical scalar theory of Airy, Lommel and Struve. The results have an immediate bearing on the resolving power of image forming systems; they also help our understanding of the significance of the scalar diffraction theory, which is customarily employed, without a proper justification, in the analysis of images in lowaperture systems.
2,636 citations
TL;DR: It is shown that, in the particular case of a tightly focused, radially polarized beam, the polarization shows large inhomogeneities in the focal region, while the azimuthally polarized beam is purely transverse even at very high numerical apertures.
Abstract: Cylindrical-vector beams are of increasing recent interest for their role in novel laser resonators and their applications to electron acceleration and scanning microscopy. In this paper, we calculate cylindrical-vector fields, near the focal region of an aplanatic lens, and briefly discuss some applications. We show that, in the particular case of a tightly focused, radially polarized beam, the polarization shows large inhomogeneities in the focal region, while the azimuthally polarized beam is purely transverse even at very high numerical apertures.
1,472 citations
TL;DR: Black or reflective particles can be trapped in the dark central minimum of a doughnut laser beam produced using a high efficiency computer generated hologram to carry angular momentum transferred from the central phase singularity beam.
Abstract: Black or reflective particles can be trapped in the dark central minimum of a doughnut laser beam produced using a high efficiency computer generated hologram. Such beams carry angular momentum due to the helical wave-front structure associated with the central phase singularity even when linearly polarized. Trapped absorptive particles spin due to absorption of this angular momentum transferred from the singularity beam. The direction of spin can be reversed by changing the sign of the singularity.
1,431 citations
TL;DR: In this paper, a spiral phaseplate can convert a TEM00 laser beam into a helical wavefront beam with a phase singularity at its axis, and the diffractive-optical effect of the spiral phase plate is implemented by index matching a macroscopic structure in an optical immersion.
1,393 citations
TL;DR: In this paper, a mode converter based on the Gouy phase was proposed to transform a Hermite-gaussian mode of arbitrarily high order to a Laguerre-Gaussian mode and vice versa.
1,275 citations