Light-controllable liquid crystal platform for microparticle oscillations and transport.

Liquid crystal colloids manifest complex motion caused by external stimuli, but tunable and addressable control of microsized objects remains a challenge. This study aims to demonstrate light-driven trapping, transport, and sustained periodic motions of microparticles by employing liquid crystal films as a light-controllable colloidal platform. The diverse motions of microscopic particles result from Marangoni convection coupled with elastic deformations in free-surface liquid crystal films subjected to light beam heating.

Multimode Robust Lasing in a Dye-Doped Polymer Layer Embedded in a Wedge-Shaped Cholesteric.

Cholesteric liquid crystals (CLCs) with induced defects are one of the most prominent materials to realize compact, low-threshold and tunable coherent light sources. In this context, the investigation of optical properties of induced defect modes in such CLCs is of great interest. In particular, many studies have been devoted to the spectral control of the defect modes depending on their thickness, optical properties, distribution along the CLC, etc.

Magnetically Induced Transparency in Media with Helical Dichroic Structure.

In our paper, the magneto-optical properties of a dichroic cholesteric liquid crystal layer with large values of magneto-optical parameter g and low values of dielectric permittivity were investigated. The solutions of the dispersion equation and their peculiarities were investigated in detail. The specific properties of reflection, transmission, absorption, rotation, ellipticity spectra and also the spectra of ellipticity and azimuth of eigen polarization were investigated.

Erratum: Spin-to-Orbital Angular Momentum Mapping of Polychromatic Light [Phys. Rev. Lett. 120, 213903 (2018)].

This corrects the article DOI: 10.1103/PhysRevLett.120.

Spin-to-Orbital Angular Momentum Mapping of Polychromatic Light.

Reflective geometric phase flat optics made from chiral anisotropic media recently unveiled a promising route towards polychromatic beam shaping. However, these broadband benefits are strongly mitigated by the fact that flipping the incident helicity does not ensure geometric phase reversal. Here we overcome this fundamental limitation by a simple and robust add-on whose advantages are emphasized in the context of spin-to-orbital angular momentum mapping.

Laguerre-Gaussian modal q-plates.

We propose space-variant uniaxial flat optical elements designed to generate pure Laguerre-Gaussian modes with arbitrary azimuthal and radial indices l and p from an incident Gaussian beam. This is done via the combined use of the dynamic and the geometric phases. Optimal design protocol for the mode conversion efficiency is derived, and the corresponding characteristics are given for -6≤l≤6 and 0≤p≤5.

Bragg-Berry mirrors: reflective broadband q-plates.

We report on the experimental realization of flat mirrors enabling the broadband generation of optical vortices upon reflection. The effect is based on the geometric Berry phase associated with the circular Bragg reflection phenomenon from chiral uniaxial media. We show the reflective optical vortex generation from both diffractive and nondiffractive paraxial light beams using spatially patterned chiral liquid crystal films.

Reflective Spin-Orbit Geometric Phase from Chiral Anisotropic Optical Media.

We report on highly reflective spin-orbit geometric phase optical elements based on a helicity-preserving circular Bragg-reflection phenomenon. First, we present a dynamical geometric phase experiment using a flat chiral Bragg mirror. Then, we show that shaping such a geometric phase allows the efficient spin-orbit tailoring of light fields without the need to fulfill any condition on birefringent phase retardation, in contrast to the case of transmission spin-orbit optical elements.