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This article is cited in 3 scientific papers (total in 3 papers)
OPTO-IT
Optical force acting on a particle in the presence of a backward energy flow near the focus of a gradient lens
A. G. Nalimovab a IPSI RAS – Branch of the FSRC "Crystallography and Photonics" RAS,
443001, Samara, Russia, Molodogvardeyskaya 151
b Samara National Research University, 443086, Samara, Russia, Moskovskoye Shosse 34
Abstract:
We show that a 70-nm dielectric nanoparticle placed on the optical axis near the surface (at a distance less than 100 nm) of a high-NA gradient microlens made of silicon, which is illuminated by a laser beam of 1.55 $\mu$m wavelength, is attracted to the lens surface with a piconewton force. The profile of the lens refractive index is described by a hyperbolic secant function. If a cut-out is made in the lens output surface, then the nanoparticle will be pulled into this cut-out, producing a kind of 'optical magnet'. If a reverse energy flow is to be generated on the optical axis near the output surface of such a gradient lens, this will lead to an absorbing dielectric nanoparticle being pulled toward the surface with a greater force than a similar non-absorbing particle. In the absence of a reverse flow, both absorbing and non-absorbing particles will be attracted to the surface with an equal force. The electromagnetic fields involved are calculated using a finite difference time domain (FDTD) method and the acting forces are calculated using a Maxwell stress tensor.
Keywords:
force, backward force, moment of force, optical tweezers, Maxwell stress tensor, rotation, gradient lens.
Received: 23.06.2020 Accepted: 25.09.2020
Citation:
A. G. Nalimov, “Optical force acting on a particle in the presence of a backward energy flow near the focus of a gradient lens”, Computer Optics, 44:6 (2020), 871–875
Linking options:
https://www.mathnet.ru/eng/co858 https://www.mathnet.ru/eng/co/v44/i6/p871
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Abstract page: | 93 | Full-text PDF : | 32 | References: | 14 |
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