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Levitated optomechanics of silica microparticles in vacuum placed in 2D and 3D optical potentials possessing orbital angular momentum (Conference Presentation)

Paper Abstract

We demonstrate the transfer of orbital angular momentum (OAM) to optically levitated microparticles in vacuum. We create two-dimensional (2D) and three-dimensional (3D) optical potentials possessing OAM. In the former case the microparticle is placed within a Laguerre-Gaussian (LG) beam and orbits the annular beam profile with increasing angular velocity as the air drag coefficient is reduced. Our results reveal that there is a fundamental limit to the OAM that may be transferred to a trapped particle, dependent upon the beam parameters and inertial forces present. Whilst a LG beam scales in size with azimuthal index, recently we have created a “perfect vortex” beam whose radial intensity profile and radius are both independent of topological charge. As the Fourier transform of a “perfect vortex” yields a Bessel beam, imaging a “perfect vortex”, with its subsequent propagation thus realises a complex three-dimensional optical field. In this scenario we load individual silica microparticles into this field where the optical gradient and scattering forces interplay with the inertial and gravitational forces acting on the trapped particle. As a result the trapped microparticle exhibits a complex three-dimensional motion that includes a periodic orbital motion between the Bessel and the “perfect vortex” beam. We are able to determine the three dimensional optical potential in situ by tracking the particle. This first demonstration of trapping microparticles within a complex 3D optical potential in vacuum opens up new possibilities for fundamental studies of many-body dynamics, mesoscopic entanglement, and optical binding.

Paper Details

Date Published: 14 March 2018
Proc. SPIE 10549, Complex Light and Optical Forces XII, 105491B (14 March 2018); doi: 10.1117/12.2290534
Show Author Affiliations
Yoshihiko Arita, Univ. of St. Andrews (United Kingdom)
Michael Mazilu, Univ. of St. Andrews (United Kingdom)
Mingzhou Chen, Univ. of St. Andrews (United Kingdom)
Tom Vettenburg, Univ. of St. Andrews (United Kingdom)
Juan M. Aunon, Univ. of St. Andrews (United Kingdom)
Ewan M. Wright, College of Optical Sciences, The Univ. of Arizona (United States)
Kishan Dholakia, Univ. of St. Andrews (United Kingdom)

Published in SPIE Proceedings Vol. 10549:
Complex Light and Optical Forces XII
Enrique J. Galvez; David L. Andrews; Jesper Glückstad, Editor(s)

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