Motion of an optically torqued nanorod: the overdamped case

TL;DR

This paper analytically solves the overdamped motion equation of an optically torqued nanorod and compares the solution with experimental observations, finding very close agreement.

Contribution

It provides an analytical solution for the overdamped nanorod motion and validates it against experimental data, advancing understanding of nanorod dynamics under optical torque.

Findings

Analytical solution matches experimental data closely

Overdamped nanorod motion described by a nonlinear differential equation

Insights into nanorod response to optical torque in viscous fluids

Abstract

A recent experiment [W. A. Shelton {\emph{et\ al.}}, Phys.\ Rev.\ E {\bf{71}}, 036204 (2005)] measured the response of a nanorod trapped in a viscous fluid to the torque produced by an incident optical frequency electromagnetic wave. The nonlinear differential equation describing this motion is similar that of a damped, driven pendulum. The overdamped limit of this equation has been solved analytically. We analyze the properties of this solution in comparison to the observations of the experiment and find very close agreement.