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In science fiction, one is quite familiar with the idea of moving objects
using laser beams, evoking concepts such as a “tractor beam”. In the
laboratory science fiction turns into science fact: a powerful technique
known as “optical tweezers” (OT) shows that micrometre-sized particles can
be grabbed, moved and generally manipulated without any physical contact
using optical forces.
This talk will begin with an overview of the field and applications esp.
using shaped light in biology. Then I will progress to give a perspective of
emergent studies in manipulation using materials science. This can include
the rotation of particles in liquid and vacuum [1] using vaterite and
nanovaterite particles. These particles exhibit a birefringence that allows
them to spin when using circularly polarised trapping beams. Such studies
can lead to very high rotation rates and exhibit new features that link to
optomechanical cooling of the particle motion and potential future studies
of quantum friction [1,2]. Further use for material properties includes
anti-reflection coated particles for enhanced optical forces [3]. The use of
these latter types of particles can lead to enhanced cell motion [4] and new
studies in optomechanics.
[1] Y. Arita, M. Mazilu, and K. Dholakia, Nature Commun 4, 2374 (2013) [2]
Yoshihiko Arita, Michael Mazilu, Tom Vettenburg, Ewan M. Wright, and Kishan
Dholakia.
Optics Letters 40(20), 4751-4754 (2015).
[3] Anita Jannasch, Ahmet F. Demirörs, Peter D. J. van Oostrum, Alfons van
Blaaderen & Erik Schäffer, Nature Photonics 6, 469–473 (2012) [4] Derek
Craig, Alison McDonald, Michael Mazilu, Helen Rendall, Frank Gunn-Moore, and
Kishan Dholakia, ACS Photonics 2(10), 1403–1409 (2015). |