منابع مشابه
Material-independent and size-independent tractor beams for dipole objects.
A Bessel beam without an axial gradient can exert a pulling force on an object [A. Novitsky, C. W. Qiu, and H. Wang, Phys. Rev. Lett. 107, 203601 (2011)]. However, it cannot be called a "tractor beam" per se, as long as the light pulling effect is ultrasensitive to the object's material and size, a perturbation of which will make the optical traction go away. In this Letter, we investigate and ...
متن کاملSingle gradientless light beam drags particles as tractor beams.
Usually a light beam pushes a particle when the photons act upon it. We investigate the optical forces by nonparaxial gradientless beams and find that the forces can drag suitable particles all the way towards the light source. The major criterion of realizing the backward dragging force is the strong nonparaxiality of the light beam, which contributes to the pulling force owing to momentum con...
متن کاملOptical conveyors: a class of active tractor beams.
We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Trapped objects can be moved selectively upstream or downstream along the conveyor by appropriately changing the Bessel beams' relative p...
متن کاملRayleigh-Debye scattering with focused laser beams.
A focused beam technique has been developed for diagnosing the characteristics of individual particles within a polydisperse ensemble. In the Rayleigh-Debye approximation the scattered fields are related to the orientation and properties of a scatterer by means of explicit analytic formulas. The results simplify when the particle size is small compared to the minimum beam diameter.
متن کاملCrack Identification and Characterization in the Rayleigh Limit
We discuss apparent characteristic features of Rayleigh scattering of elastic waves from cracks. Interpreting these features, we propose a procedure that in some experimental situations may be useful to distinguish generally-shaped cracks from volume defects. For elliptically-shaped cracks, we propose additional procedures that in principle allow the unique specification of crack size, shape an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review A
سال: 2016
ISSN: 2469-9926,2469-9934
DOI: 10.1103/physreva.93.043807