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In structured light tweezers, it is a challenging technical issue to realize the complete circular motion of the trapped particles parallel to the optical axis. Herein, we propose and generate a novel optical skipping rope via combining beam shaping technology, Fourier shift theorem, and beam grafting technology. This optical skipping rope can induce the transverse orbital angular momentum (OAM) (i.e., nominal OAM, whose direction is perpendicular to the optical axis) and transfer it to the particles, so that the particles have a transverse torque, thereby causing the particles to rotate parallel to the optical axis. Experimentally, our optical tweezers validate that the designed optical skipping rope realizes the orbital motion of polystyrene particles parallel to the optical axis. Additionally, the experiments also demonstrate that the optical skipping ropes manipulate particles to move along the oblique coil trajectory and three-dimensional (3D) cycloidal trajectory. Using the laser beam induced OAM, this innovative technology increases the degree of freedom for manipulating particles, which is of great significance for the application of optical tweezers in optical manipulation, micromechanics, and mimicry of celestial orbits.

Optical pulling forces exerted on small particles can be achieved by tailoring the properties of the electromagnetic field, the particles themselves, or the surrounding environment. However, the nonlinear optical effect of the surrounding environment has been largely neglected. Herein, we report the optical pulling forces on a Rayleigh particle immersed in a nonlinear optical liquid using high-repetition-rate femtosecond laser pulses. The analytic expression of time-averaged optical forces allows us to better understand the underlying mechanism of the particle transportation. It is shown that the two-photon absorption of the surrounding liquid gives rise to a negative radiation force. Transversely confined Rayleigh particles can be continuously dragged towards the light source during a pulling process.

Recently there is an increasing interest in complex optical fields with spatially inhomogeneous state of polarizations and optical singularities. Novel effects and phenomena have been predicted and observed for light beams with these unconventional states. Nanostructured metallic thin film offers unique opportunities to generate, manipulate and detect these novel fields. Strong interactions between nano-metallic surfaces and complex optical fields enable the development of highly compact and versatile functional devices and systems. In this review, we first briefly summarize the recent developments in complex optical fields. Various nano-metallic surface designs that can produce and manipulate complex optical fields with tailored characteristics in the optical far field will be presented. Nano-metallic surfaces are also proven to be very effective for receiving and detection of complex optical fields in the near field. Advances made in this nascent field may enable the design of novel photonic devices and systems for a variety of applications such as quantum optical information processing and integrated photonic circuits.

Optical trapping and manipulation using focused laser beams has emerged as a powerful tool in the biological and physical sciences. However, scaling this technique to metallic nanoparticles remains challenging due to the strong scattering force and optical heating effect. In this work, we propose a novel strategy to optically trap metallic nanoparticles even under the resonant condition using engineered optical field. The distribution of the optical forces can be tailored through optimizing the spatial distribution of a vectorial optical illumination to favour the stable trapping of a variety of metallic nanoparticles under various conditions. It is shown that this optical tweezers has the ability of generating negative scattering force and supporting stable three-dimensional trapping for gold nanoparticles at resonance while avoiding trap destabilization due to optical overheating. The technique presented in this work offers a versatile solution for trapping metallic nanoparticles and may open up new avenues for optical manipulation.

The spatial self‐phase modulation (SSPM) of phosphorus‐based nanomaterials is widely studied and developed as passive nonlinear photonic devices for applications in all‐optical switches, logic gates, information converters, etc. In this work, violet phosphorus quantum dots (VP QDs) are prepared and characterized in three different solvents, their SSPM is investigated, and their spatial asymmetric light propagation performances are demonstrated. It is shown that VP QDs prepared in three different solvents exhibit different bandgaps, mainly due to the interaction between the dangling bonds of VP QDs and functional groups in different solvents. The SSPM experiment characterizes the nonlinear optical response of solvent‐dependent VP QDs. It is found that VP QDs exhibit strong nonlinear optical effect and their nonlinear refractive indexes are comparable to other phosphorus‐based 2D materials. Unlike the previously reported principle of spatial asymmetric light propagation (i.e., a cascaded sample based on SSPM composed of nanomaterials with excellent nonlinear refraction and SnS2 with reverse saturation absorption), the spatial asymmetric light propagation performance based on SSPM is demonstrated using a cascaded sample of VP QDs with significantly different nonlinear optical response prepared in two different solvents. [ABSTRACT FROM AUTHOR]

Photonic spin-Hall effect is significantly magnified in a curved hyperbolic metamaterial (hyperlens) with hyperbolic dispersion. We theoretically and numerically analyze the magnification of the photonic spin-Hall effect from a single dipole emitter. Through studying the dispersion of the curved hyperbolic metamaterial, a maximum half angular separation of 45.0° between the right-handed circular and left-handed circular polarization channels can be obtained. Moreover, the curved hyperbolic metamaterial can provide a complete separation of the spin dependent radiation channels. Such a magnified photonic spin-Hall effect may find potential applications in quantum information processing, directional switching, and polarization sorting. [ABSTRACT FROM AUTHOR]