Confinement and Tracking of Brownian Particles in a Bessel Beam Standing Wave

Optical trapping is a useful tool for manipulating microscopic particles and probing the physical interactions of matter. However, previous optical trapping techniques introduced complications for analyzing Brownian particle diffusion in viscous media because they either restricted the particles' motion or trapped the particles too close to a surface. To our knowledge, this thesis presents the first realization of two-dimensional, transverse tracking of Brownian microparticles in multiple, surface-isolated traps. To accomplish this, we used an axicon-generated, zeroth-order Bessel beam standing wave whose parameters were adjusted to allow tight axial confinement and loose transverse confinement of microscopic-sized particles in the central maximum of the Bessel beam. We chose a Bessel beam because its unique non-diffracting and self-healing properties provided distinct advantanges over a Gaussian beam. In particular, a Bessel beam standing wave was shown to produce optical potential wells that are more abundant, uniform, and stable than those of a Gaussian standing wave.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2015

Author dc:creator

• McKell, Chad

• Bessel beam

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/57431

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/57431