English
Related papers

Related papers: Opto Propeller Effect on Chiral Micro-Rotors

200 papers

We report on the observation and measurement of the transfer of transverse angular momentum to birefringent particles several wavelengths in size. A trapped birefringent particle is much larger than the nano-particles systems for which…

The rotational response of quantum condensed fluids is strikingly distinct from rotating classical fluids, especially notable for the excitation and ordering of quantized vortex ensembles. Although widely studied in conservative systems,…

We propose an enantioselective scheme to sort homogeneous chiral particles using optical tweezers. For a certain range of material parameters, we show that a highly focused circularly-polarized laser beam traps particles of a specific…

Optics · Physics 2023-07-19 R. Ali , F. A. Pinheiro , R. S. Dutra , F. S. S. Rosa , P. A. Maia Neto

A linearly polarized Gaussian beam, carrying zero net spin angular momentum, is conventionally not expected to exert optical torque or induce rotational motion in birefringent microparticles. When such a beam is tightly focused, the…

We report for the first time the theory of optical tweezers of spherical dielectric particles embedded in a chiral medium. We develop a partial-wave (Mie) expansion to calculate the optical force acting on a dielectric microsphere…

Optics · Physics 2020-09-28 Rfaqat Ali , R. S. Dutra , F. A. Pinheiro , F. S. S. Rosa , P. A. Maia Neto

Bio-compatible Au nanoparticles exhibit great advantages in the application of biomedical researches, such as bio-sensing, medical diagnosis, and cancer therapy. Bio-molecules can even be manipulated by laser tweezers with the optically…

Optics · Physics 2022-02-16 Yang Li , Jing Wang , Hai-Qing Lin , Lei Shao

Advances in optical trapping design principles have led to tremendous progress in manipulating nanoparticles (NPs) with diverse functionalities in different environments using bulky systems. However, efficient control and manipulation of…

Optical trapping, where microscopic particles are trapped and manipulated by light is a powerful and widespread technique, with the single-beam gradient trap (also known as optical tweezers) in use for a large number of biological and other…

Optics · Physics 2007-05-23 T. A. Nieminen , H. Rubinsztein-Dunlop , N. R. Heckenberg

Magnetic nano/microrotors are passive elements that spin around an axis due to an external rotating field while remaining confined to a close plane. They have been used to date in different applications related to fluid mixing, drug…

Soft Condensed Matter · Physics 2025-01-28 Dolachai Boniface , Arthur V. Straube , Pietro Tierno

Circular dichroism is the differential rate of absorption of right- and left-handed circularly polarized light by chiral particles. Optical vortices which convey orbital angular momentum (OAM) possess a chirality associated with the…

Optics · Physics 2021-05-26 Kayn A. Forbes , Garth A. Jones

We study a nanofabricated silicon rod levitated in an optical trap. By manipulating the polarization of the light we gain full control over the ro-translational dynamics of the rod. We are able to trap both its centre-of-mass and align it…

We concentrate on the forces and torques exerted on transparent and absorbing particles trapped in laser beams containing optical vortices. We review previous theoretical and experimental work and then present new calculations of the effect…

We demonstrate a new method for determining the radius of micron-sized particles trapped by a vortex laser beam. The technique is based on measuring the rotation experienced by the center of mass of a microsphere that is laterally displaced…

In this study, we investigate the thermocapillary rotation of microgears at fluid interfaces and extend the concept of geometric asymmetry to the translational propulsion of micron-sized particles. We introduce a transient numerical model…

Fluid Dynamics · Physics 2024-06-24 Tillmann Carl , Clarissa Schoenecker

We present an optical tweezer based study of rotation of microscopic objects with shape asymmetry. Thermal fluctuations and rotations are simultaneously monitored through laser back scattering. The rotation results in a modulation in…

Soft Condensed Matter · Physics 2011-02-16 Yogesha , Sarbari Bhattacharya , Sharath Ananthamurthy

The recoil optical force that acts on emitters near a surface or waveguide relies on near-field directionality and conservation of momentum. It features desirable properties uncommon in optical forces, such as the ability to produce it via…

Optics · Physics 2020-07-02 J. A. Girón-Sedas , Francisco J. Rodríguez-Fortuño

Interfacial polar molecules feature a strongly anisotropic response to applied electric field, favoring dipole orientations parallel to the interface. In water, in particular, this effect combines with generic orientational preferences…

Soft Condensed Matter · Physics 2017-02-08 Dusan Bratko , Christopher D. Daub , Alenka Luzar

We present a method to measure the optical torque applied to particles of arbitrary shape held in an optical trap, inferred from the change of angular momentum of light induced by the particle. All torque components can be determined from a…

Magnetic skyrmions are chiral quasiparticles that show promise for future spintronic applications such as skyrmion racetrack memories and logic devices because of their topological stability, small size (typically $\sim3-500$ nm), and…

Mesoscale and Nanoscale Physics · Physics 2018-04-02 Wenrui Yang , Huanhuan Yang , Yunshan Cao , Peng Yan

Optical tweezers are powerful tools for high resolution study of surface properties. Such experiments are traditionally performed by studying the active or the brownian fluctuation of trapped particles in the X, Y, Z direction. Here we find…

Optics · Physics 2018-11-13 Rahul Vaipully , Dhanush Bhatt , Anand Dev Ranjan , Basudev Roy