This PDF file contains the front matter associated with SPIE Proceedings Volume 11522, including the Title Page, Copyright information, and Table of Contents.

Beam shaping is an essential ingredient of photonic technologies and emerging applications based on inhomogeneous light fields motivate the exploration of various approaches to spatially structure the main features of a light beam, such as intensity, phase, or polarization state. The advent of micro/nanofabrication technologies nowadays offer novel opportunities to exploit the spin-orbit interaction of light for shaping the complex amplitude of light. Here we discuss how phase and amplitude could be spatially shaped in order to achieve Laguerre-Gauss modal beam shapers. This requires to account for the effects of both dynamic and geometric phase and experimental realization is yet to me demonstrated.

Metallic nanostructures can be designed to act not only as nanoscale optical antenna but also as much localized heat sources. Although both aspects are usually independently investigated, we conduct here a multiphysics approach to design multipurpose plasmonic nanogap antennas. On the one hand, by mean of a hydrothermal synthesis reaction, we make use of the localized heat production to control the growth of a ZnO layer at the surface of the targeted part of a gold nanoantenna. On the other hand, the fabricated hybrid plasmonic-photonic nanoantenna allows for large electric field enhancement inside ZnO-filled plasmonic nanogaps. Such nanodevice could find application as nanoscale light source.

It has been expected that the gradient force in the electric field induced by the excitation of the localized surface plasmon resonance (LSPR) could retard the molecular Brownian motion, if molecules has enough polarizability to generate optical force beyond thermal fluctuation. In this study, we have attempted to observe the optical molecular manipulation at the gap of plasmonic bow-tie nanostructures in the bi-analyte solution of molecules. Through the evaluation of the surface diffusion process by electrochemical surface-enhanced Raman scattering (SERS) measurements, it has been found that the control of the electrochemical potential of the metal nanostructures realized the molecular selective manipulation. In addition, we have successfully observed the formation of unique phase of molecule condensation at electrified interface.

We demonstrated that ultrafast azimuth rotation of linearly polarized beam by use of a chirped optical pulse pair, and the rotational frequency of sub-THz was realized.

Polystyrene and silica nanoparticles are gathered and form a single disk-like assembly at glass/solution interface upon optical trapping with a focused laser and its size evolves much larger than the focal volume. In addition, linearly aligned aggregates of nanoparticles are prepared at specific edge sites of the assembly, which looks like horns. Transmission spectral and diffraction pattern measurements were carried out, confirming a correlation between the central arrangement of the nanoparticles and the horn formation. This dynamics and mechanism characteristic of optical trapping at interface is discussed from the viewpoint of optical propagation of the trapping laser. The assembly formation started at the focus where trapping laser light is scattered, and the trapping laser propagated trough the prepared assembly expanding its size.

We revisit the principle of transverse ion flow V measurement by using an optical vortex beam (OVB). We first derive azimuthal Doppler shift with conservations of momentum and energy of the atom that is excited by the OVB, unlike the original paper [L. Allen et al., Optics Communications 112, 141 (1994).]. Then, we consider the feasibility of plasma flow velocity measurement which measure the Doppler shift with using a surface-processed photonic-crystal laser. It shows that the beam radius in a typical case is required to be less than approximately 60 μm for V~10⁵ m/s and topological charge l = 2.

We report on the generation of a spinning twin-mode with two bright spots in a biomaterial, bacteriorhodopsin (bR), suspension pumped by an optical vortex. The spinning direction of the twin-mode is fully assigned by the handedness of the incident optical vortex. This phenomenon occurs owing to the spatial soliton effects in the bR suspension.

A modified interferometer that introduces position and momentum shifts in mutually orthogonal directions can transform optical modes by raising and lowering radial and azimuthal mode indices. The action of this interferometer can be generalized in the form of a pair of twisting operators, which can be further written in terms of the ladder operators of the 2-dimensional harmonic oscillator. For lower order input modes there is good agreement between theory and experiment, but as the input mode becomes more complex, experimental results start to deviates from first-order theory. This is due to the shifts becoming larger relative to beam structure. We discuss how higher order corrections can be calculated for such cases.

Highly localized electric field induced by the excitation of the localized surface plasmon provides huge gradient of the field intensity in nano-scale. Such gradient results in exotic perturbation for molecules at electrified interfaces with plasmonically-active metal nanostructures. In this study, plasmon-induced hydrogen evolution reactions have been successfully induced by the combination of the plasmonic metal nanostructures on the p-type GaP semiconductor electrode. Through various photoelectrochemical measurements, it was found that the present system showed the relatively higher efficiency under the neutral condition compared with the acidic and the basic conditions. In addition, the unique molecular process has been observed by using the isotopic water molecules. By the examination of the isotopic effect, the effect of the field localization on the reaction was discussed.

The authors reported that laser illumination to a metal sphere in glass migrated the metal sphere toward the light source. The migration was caused by interfacial tension gradient. In this presentation, we demonstrate the metal sphere separation by the two laser beam illumination from opposite direction. The metal sphere separation was not explained by the interfacial gradient and suggested the existence of pulling force to the light source side.

Atom interferometry is an advanced optical manipulation tool of atoms in precision measurement field. Wavefront aberrations of the Raman beam have become one of the major obstacles impeding the improvement of measurement accuracy. Beforehand measurement of laser wavefront is impractical due to the further wavefront deterioration during optical mounting. In this work, we present a general method for evaluating the effective Raman wavefront that atoms experience and the corresponding phase shift of interferometric fringes. The method extracts the effective Zernike polynomial terms and reconstructs the wavefront using optimal estimation theory. The evaluation accuracy and convergence speed are discussed by simulation. The results predict the method adaptability and provide strong support on analytical and numerical reference for wavefront error compensation.

Optical trapping of nanoparticles is realized by optical gradient force originated from the intensity gradient of light with a focused beam. It is expected that the gradient force depending on the circular polarization (CP) acts on particles with chiral structures. Here, we investigate the CP-dependent gradient force on the chiral gold nanoparticles. We found that the amplitude (dispersion of the position of the Brownian motion) depends on the handedness of the incident light in both cases of D- and L-form particles. Based on the results on the gradient force for the chiral particles, it is expected that chiral nanomaterials can be handled by the circularly polarized light.

Elliptically polarized evanescent electromagnetic fields can exert a transverse optical force on scattering objects immersed in such fields. We demonstrate this experimentally by setting isotropic, dielectric microspheres into orbital motion around a single-mode ultrathin fiber waveguide. In accordance with the theoretical results, the observed orbiting frequency is proportional to the helicity parameter, which is controlled by the degree of circular polarization of the light coupled to the fiber. The microparticles are rotating against the direction of the energy flow circulation around the fiber, thus verifying the theoretically expected negative optical torque. An important prerequisite for the measurements was the complete polarization control for the ultrathin fiber.

In recent years various experiments reported translational and rotational motion of laser-heated Janus colloids, including steering through feedback and collective effects. We discuss optical actuation and swimming mechanisms, in terms of the underlying thermal surface forces and slip velocities, the latter providing hydrodynamic boundary conditions.

We experimentally investigated the manipulation of mica flakes using photothermally induced microbubbles. Iron silicide was sputtered on mica flakes to absorb the laser light and convert it to heat. By focusing a laser on to the flake immersed in degassed water, a water vapor microbubble was generated on the flake. The bubble involved strong Marangoni flow due to the steep temperature gradient on it. Laser irradiation at multiple spots allowed us to control the direction of the temperature gradient and subsequent Marangoni flow. By generating the flow parallel to the flake surface, the flake was driven on the glass substrate. This method is expected as a novel method to manipulate large and heavy particles in microfluidic channels.

It has been shown that electromagnetic fields carrying orbital angular momentum can twist the surface of an azobenzene polymer film, creating micro- and nano-scale structures. In this work, we have extended these calculations from vortex beams to vector beams by presenting an analysis of the induced-force density due to structured optical beams onto a dispersive-absorptive medium at two different regimes: paraxial and non-paraxial beams. From this, we have shown that it is possible to create much more complex patterns that could be of interest for nanostructuring azo-polymer surfaces.

All-fiber platforms specially designed for optical manipulation of solid particles and liquid droplets are reviewed in terms of the physical principles, waveguide structures, and optical manipulation techniques. Firstly, fiber optic Bessel-like beam generators in two different schemes 1) micro-Fourier optics, and 2) multimode interference are explained. Open-loop and closed-loop circulation of solid particles using the fiber optic Bessel-like beams are discussed. Finally, nanodroplet generation using a hollow optical fiber will be introduced.

Most organic solvents a have higher refractive index than water. Therefore, they can be optically trapped in the form of microdroplet. We report our attempt to trap a single chloroform microdroplet in water. Several factors are to be considered in the trapping such as mixing ratio and power density.

In the present study, we have detected multiphoton absorption force acting on microparticles due to simultaneous twophoton absorption. A polymer microparticle including dye molecules was optically trapped with femtosecond (800 nm, 100 fs) pulse pairs with time-interval Δt in water. Under the condition that Δt > the pulse duration, the particle was trapped with absorbing small number of photons via multiphoton process. The number of photons absorbed via simultaneous two-photon absorption increased by decreasing Δt to overlap the pulse pair, leading to the micromechanical motion of the particle. By tracking the position of the trapped particle, we confirmed that the particles were pushed in the direction of light propagation and the displacement increased with decreasing Δt.

We demonstrate synthesis and crystallization of lead halide perovskites under the focused laser irradiation in the unsaturated precursor solutions. Upon the irradiation onto the air/solution interface, a perovskite crystal is formed from the focal spot. The synthesized crystal collects more precursors and grows large while trapped at the focus. The formed crystal dissolves after the laser turns off, which is due to unsaturated condition of the surrounding solution. The mechanism of the crystallization is discussed from the viewpoints of laser heating and laser trapping.

Optical forces may provide an elegant solution to achieve optical sorting of nanoparticles according to their optical properties. Yet, efficient nanoparticle optical sorting would require all the nanoparticles to be gathered and kept inside the light path for a sufficient time. In order to overcome nanoparticle diffusion, we investigate the use of tapered glass capillaries as optofluidic waveguides. We demonstrate size-dependent optical transport of fluorescent nanodiamonds inside a tapered capillary. Particle velocities reaching few tens of micrometers per second were achieved, and size estimations are performed based on the nanoparticles’ velocities. Nanoparticle sorting is also demonstrated by balancing the optical transport of the nanodiamonds with a liquid flow in the opposite direction.

Quantitative evaluation of optical forces on nanoscale objects caused by optical vortices is significant for application of optical vortex to nanotechnology. In this study, we analyze an orbital motion of single gold nanoparticles with a diameter of 150 nm driven by the Laguerre-Gaussian beam. A nanofluidic channel with a height of 300 nm is used to confine the orbital motion into two-dimensional plane by restricting their Brownian motion perpendicular to a focal plane of objective lens, resulting in the visualization by dark-field microscopy. A particle tracking analysis of the acquired images allows the quantitative evaluation of optical forces, such as trapping stiffness and driving force of the orbital motion, and show a reasonable agreement with a theoretical estimation.

A spherical superconducting micro-particle generated by laser ablation in superfluid helium is trapped in a quadrupole magnetic field. Utilizing the property that the particle is isolated in space, observation of the Mie scattering from this particle has been carried out. Analyzing the results, information on the optical properties of superconducting microparticle and their shapes at helium temperature have been deduced.

Micro- and nanoparticles in a solution under the irradiation of an optical vortex are considered using a mathematical model based on fluid mechanics. The particles exhibit an inherent Brownian motion due to their small sizes. In particular, we consider the case of plural particles trapped in the orbit of the optical vortex expressed by the Laguerre-Gaussian beam. The inter-particle interaction includes not only repulsive forces between the particles but also the forces arising from a hydrodynamic effect. To be more specific, the flow of a solvent induced by the motion of a particle affects the motion of the other particles. The numerical simulation of the model shows that the orbital speed of the particles increases as the number of particles in the orbit.

We theoretically analyzed Photoinduced force microscopy (PiFM) measurement on dimer molecules, using discrete dipole approximation. We obtained PiFM images of a dimer molecule for allowed and forbidden optical transitions. The PiFM images reflect the spatial structure of the localized electric field vectors. This study shows that PiFM provides multifaceted information based on the microscopic interaction between nanomaterials and light.

We report that localized surface plasmon resonance allows a single-element nanostructure to induce an extrinsic angular momentum of light in its interaction with a propagating plane wave. The recoil of the angular momentum results in an optical torque on the structure along an axis perpendicular to the optical axis, and the characteristics of this transverse torque depend on the incident polarization state, including the spin direction. Our results suggest that the designed dark plasmon mode can provide a new degree of freedom for optical manipulation of nanoparticles smaller than the diffraction limit.

We present single-shot fast phase information retrieval without interferometry in the holographic data storage. Noninterferometry systems are more compact and stable than interferometric ones. Only single-shot of the intensity distribution on the Fourier plane is required to retrieve the phase information. Enhanced iterative Fourier transform algorithm (IFTA) was developed by applying embedded known phase data and phase only modulation as the prior constraints, which can be provided easily as the code rule in holographic data storage system. Strong intensity distribution on the Fourier plane reduces the requirement of high-power laser and high material diffractive efficiency. The bit-errorrate (BER) can be decreased to 0 in the simulation study. We realized BER without check code in the order of 10^-2 for 4 level phase retrieval experimentally. The code rate is increased by 2.8 times using 4 level phase code compared to with amplitude code.

A non-interferometric phase retrieval method in collinear holographic data storage (HDS) is proposed. Noninterferometric system is stable which is suitable for phase-modulated HDS but non-interferometric phase retrieval algorithm replies on strong constraint to shorten iteration number. Embedded data can provide strong constraint. However, in off-axis system, embedded data have to be in the signal part which sacrifice code rate. Our proposed collinear system considers the reference beam as embedded data to increase the code rate by about 2 times.

We successfully demonstrated the manipulation of CdSe/ZnS quantum dots with a diameter of nearly 6 nm in organic solvent at room temperature by applying an intense electric field (1.7 MV/m) under resonant optical excitation (the wavelength 532nm). From the time-variation of the quantum dot distribution monitored by fluorescence imaging, it was experimentally found that the quantum dots gather around the local maximum of the electric field intensity and the potential energy applied on the quantum dot under the optical excitation is estimated to be nearly 400 K, which is approximately 20 times larger than that expected with conventional dielectrophoresis. Such a large potential energy is considered to be due to the Stark effect of the exciton created in the optically excited quantum dot.

Ring-shaped colloidal Au-Ag nanoparticles were successfully synthesized via galvanic replacement of Ag nanoplates as a template. The average size of Au-Ag nanorings was ca. 18 nm in diameter and its average width was ca. 4 nm. The thus-obtained nanorings showed a intense localized surface plasmon resonance (LSPR) peak at 680 nm. The Au-Ag nanorings exhibited an electrocatalytic activity for oxygen reduction reaction in an O2-saturated KOH aqueous solution at negative potential than +0.8 V vs. RHE, the activity being enhanced by the photoexcitation of LSPR.

In this work, we perform an in-depth theoretical study on the Spin/Orbital Angular Momentum conversion at the nanoscale when a radially polarized vortex beam is ideally focused by a so called-hyperlens, which can support the propagation of the evanescent wave can break the diffraction limit. Radially polarized optical vortex beam was used as an input and from the output side, a beam with circular polarization was observed from the hyperlens, which enabled a unique Spin/Orbital Angular Momentum conversion at the extremely tight focal spot of the hyperlens.

A development of microlenses achromatically corrected for near infrared range is reported. Internal nanostructurization of microlens allows to obtain an effective parabolic gradient index profile. A standard stack-and-draw method was used to fabricate the microlens. They have a nearly wavelength-independent working distance of 35 μm over the wavelength range of 600-1550 nm. The proposed achromatic microlens can be applied in micro imaging systems and for wavelength independent coupling into optical fibers.

The concentration of photosen-sitizer is an important factor affecting the properties of holographic materials. Most researchers use doping or copolymerization methods to increase the saturation dissolvability of photo-sensitizer. However, the addition of multiple components will reduce the molecular mass of the photoproducts and the polymer substrate, resulting in poor stability of the grating. In this paper, we studied the solubility of phenanthraquinone (PQ) in MMA at different temperatures. At 60 °C, the solubility of PQ could reach 1.8%. Meanwhile, we found that the thermo-initiator concentration of 2,2-Azobis(AIBN) affected long-chain carbon polymerization. Therefore, proper concentration balance has a huge impact on the performance of the materials. Finally, we obtained a relatively suitable concentration balance of PQ/PMMA photopolymer, making it more suitable for volume holographic data storage.

Industrial promising structural colors based on subwavelength scale structure inevitably entail very high fabrication costs in artificial implementation. To reduce the costs, we fabricated the microstructure that necessary to realize the structural color through Au nano-islands, which can be manufactured by bottom-up chemical process instead of strict topdown process and developed a device that can adjust color quantitatively. Notably, this device has the color tunability through the refractive index of the solution that infiltrates the device and is expected to be used in the field of sensors or anti-counterfeiting devices.

This paper focuses on the causes of bubbles in the fabrication of holographic storage materials phenan- threnequinone(PQ)/polymethyl methacrylate(PMMA).Three main possibilities for generating bubbles are proposed.Azodiisobutyronitrile(AIBN) decomposes to generate nitrogen,which cannot diffuse to generate bubbles.The temperature is too high,and the local boiling of methyl methacrylate(MMA) produces bub- bles.Bubbles caused by changes in material volume.Simulation and experimental verification of the three cases show that the main reason for the generation of bubbles is the sudden shrinkage of the material.It is determined that the temperature is the second in uencing factor.

We report for the first time, to the best of our knowledge, a simple single pixel imaging (SPI) scheme with high singalto- noise ratio (SNR) in an entire THz frequency region (1 - 15 THz) by employing a thin metallic ring with a series of random masks directly perforated, that is a ‘metallic randon ring’. This SPI scheme allows us to reconstruct highresolution images (320 x 320 pixels), and it offers potentially advanced THz imaging technologies, such as non-invasive assignment of biomaterials.

We demonstrate the formation of chiral surface relief of azo-polymers by irradiation of picosecond 1-μm optical vortex with a pulse width of 8ps via two-photon absorption. Optical vortex induced TPA enables us to create the chiral surface structures only within an extremely narrow defocusing tolerance with high three-dimensional (longitudinal and transverse) spatial resolution beyond the diffraction limit and without undesired outer rings of Airy pattern.

We discover an entirely novel phenomenon, so-called the formation of curved “spin-jet”, in which an irradiated fractional optical vortex provides a donor film non-axisymmetric torque to form a “spin-jet” with a curved trajectory. This phenomenon allows the development of a novel pattering technology to scan the ejected donor dots without any mechanical systems.

We demonstrate successfully the creation of a microscale lead halide perovskite crystal by employing optical vortex laser induced forward transfer (OV-LIFT) technology. The created microscale crystals exhibit efficient visible (cyan~green~red) fluorescence with a lifetime of ~7 ns.

High-pressure microscopy is one of the powerful techniques that manipulate molecular machines working in cells. We successfully developed a new high-pressure microscope that is optimized both for the best image formation and for stability under high hydrostatic pressure. The techniques described here could be extended to study various biological samples, including molecules, cells and individuals.

AMPA-type glutamate receptor (AMPAR) is one of neurotransmitter receptors at excitatory synapses in neuronal cell. For realizing the artificial control of synaptic transmission, we have applied optical trapping of quantum-dot (QD) conjugated AMPARs on neuronal cells. Here, we demonstrate simultaneous measurement combined with optical trapping and patch-clamp recordings to evaluate the neuronal electrical activity. The relationship between optical trapping dynamics of QD-AMPARs located on neuronal cells and the neuronal electrical activity was discussed.

The global quantum network requires the distribution of entangled states over long distances, with significant advances already demonstrated using polarization, reaching approximately 1200 km in free space and 100 km in optical fiber. While Hilbert spaces with higher dimensionality, e.g., spatial modes of light, allows higher information capacity per photon, such spatial mode entanglement transport requires custom multimode fiber and is limited by decoherence induced mode coupling. Here we circumvent this by transporting multi-dimensional spatial entangled states down conventional single-mode fiber (SMF). We achieve this by entangling the spin-orbit degrees of freedom of a bi-photon pair, passing the polarization (spin) photon down the SMF while accessing multiple orbital angular momentum (orbital) sub-spaces with the other, thereby realizing multi-dimensional spatial entanglement transport. We show high fidelity hybrid entanglement preservation down 250 m of SMF across multiple 2 x 2 dimensions, which we confirm by quantum state tomography and Bell violation measures. This work offers an alternative approach to spatial mode entanglement transport that facilitates deployment in legacy networks across conventional fiber optic links.

We investigate the structures on a silicon (111) substrate produced by illumination of optical vortex. The fabricated structures on silicon (111) exhibit polycrystalline properties associated with rather complicated 7×7 constructed surface.

We used a scanning near-field optical microscope (SNOM) to observe the near-field distribution of surface plasmon polaritons (SPPs) from a ring-shaped metasurface under illumination of circularly polarized light. It was found that with an additional degree of freedom of the geometric phase provided by the regularly arranged metamolecules, control over the near-field interference of the SPPs can be achieved, which is governed by the metasurface geometric symmetry that can be tuned by its topological charge. Meanwhile, the planar chiral character of the metamolecules exerts a deep influence on the near-field interference patterns. Our results can pave the way for active control of SPP propagation in near fields, and have potential applications in highly integrated optical communication systems.

Superfluid helium is an important model system to study quantum hydrodynamics. Numerous researches have been reported on fascinating phenomena including superfluidity, unusually low viscosity, and the emergence of the quantum vortex. Here, we demonstrated the visualization of the quantum vortices, which are intrinsically unable to be seen. We prepared many nanoparticles in superfluid helium by using the laser ablation technique. The fabricated nanoparticles are trapped at the core of the quantum vortices. By imaging the scattered light from the nanoparticles, we visualized the motion of the quantum vortices.

When particles are held in optical tweezers, we assume that they are in thermal equilibrium, in which the equipartition of energy determines the position variance of optically trapped spheres. Here we show that this condition only holds for very high symmetry cases, e.g. perfectly isotropic particles in unaberrated, linearly polarized Gaussian traps. We report an experimental observation that when a birefringent microsphere is held in a linearly polarised Gaussian optical trap in vacuum, spontaneous oscillations emerge that grow rapidly in amplitude and become increasingly coherent as the air pressure is reduced. Furthermore, when parametrically driven, these self-sustained oscillators exhibit an ultrahigh mechanical quality factor > 2 x 10⁸, which can be highly sensitive to external purtabations.

We demonstrate that metal-carbonyl compounds in liquid n-hexane are dissociated and adsorbed on gold surfaces upon vibrational excitation. We illuminate gold nanoantennas with temporally-shaped mid-infrared pulses to produce intense plasmonic near-fields. The produced near-fields induce vibrational ladder climbing and the resultant dissociation of metal-carbonyl compounds. A new band, cumulatively increase with irradiation, is attributed to the molecular species which are dissociated and adsorbed on gold surfaces. This demonstration proves that the plasmonic near-fields of midinfrared pulses are useful for mode-selective reaction control at electronic ground states and for possible subsequent manipulation of molecules like trapping and alignment.

We applied three-dimensional super-resolution microscopy (3D-SRM) to fluorescence correlation spectroscopy (FCS). According to our predictions, this method can provide a spherical fluorescence spot area with atto-liter (10^-18ℓ) volume, which is much smaller than that given by conventional FCS. Actually, the inflection point of the measured correlation function (CF) applied by 3D-SRM shifted to the shorter correlation time domain compared with that of conventional FCS. This result means that the effective fluorescence spot size becomes shrunken owing to 3D-SRM. This spot enables us to analyze diffusive motion of highly concentrated molecules in a small volume. It is expected that our proposed method can be applied to elucidating life phenomena as well as chemical dynamics.

Using light, living cells can be manipulated to form several centimeter long waveguide structures, capable of guiding light through scattering media. Here, we will discuss some results of self-trapping and guiding of light in biological suspensions of different cells, including cyanobacteria, E. coli, and red blood cells. A forward-scattering theoretical model is developed which helps understand the experimental observations. Formed waveguides can provide effective guidance for weaker light through scattered bio-soft-matter. The ability to transmit light through turbid fluids with low loss could open up the possibilities for deep-tissue imaging, as well as noninvasive treatment and diagnostics.

The idea of exchanging angular momentum between microscopic parts and the outside world has been a key idea in many recent experiments involving nano-photonic technologies. Indeed, many experiments with optical tweezers involve the application of tailored beams with orbital angular momentum to microscopic particles. A variety of such beams can be created with modern computer-generated holograms such as spatial light modulators. However, often little consideration is given to the application of these beams after they have been generated. Here we will discuss the measurement and application of beams with orbital angular momentum under the microscope. Specifically, measurement of the applied optical torque, distortion and rotation of beams carrying OAM. Finally, we will discuss the application of vortices in topological insulators.

Optical tweezers have contributed substantially to the advancement of micro-manipulation. However, they do have restrictions, mainly the limited range of materials that yield to optical trapping. Here we propose a method of employing optically trapped objects to manipulate the surrounding fluid and thus particles freely diffusing within it. We create and investigate a reconfigurable active-feedback system of optically trapped actuators, capable of manipulating translational and rotational motion of one or more nearby free objects.