Professor Keith Bonin – WFU Department of Physics Professor and Associate Provost for Research and Scholarly Inquiry
George P. Williams, Jr. Lecture Hall, (Olin 101)
Wednesday, September 19, 2018, at 4:00 PM
There will be a reception with refreshments at 3:30 PM in the lounge. All interested persons are cordially invited to attend.
Here we create a series of optical corrals and calculate their potential energy profile. A standing-wave Bessel beam is used to form traps in one dimension (along the optical axis of the laser beam) and corrals in two dimensions, in planes perpendicular to the optical axis at the antinodes of the standing waves. These optical corrals are formed by an axicon-generated Bessel beam that is reflected back onto itself.
We report on Mie calculations of the 2D optical corrals and then compare the resulting probability distributions to those observed for latex beads of diameters 100, 200, and 300 nm. The experimental radial probability density function of tracked particles closely mimics the theoretical optical structure of a Bessel standing-wave corral. The Bessel standing-wave corrals we have characterized can be used to measure rotational diffusion and torques on micro- and nanorods to help understand microfluidic behavior.