Optical tweezers toolbox: better, faster, cheaper; choose all three

Abstract

Numerical computation of optical tweezers is one path to understanding the subtleties of their underlying mechanism-electromagnetic scattering. Electromagnetic scattering models of optical trapping can be used to find the properties of the optical forces and torques acting on trapped particles. These kinds of calculations can assist in predicting the outcomes of particular trapping configurations. Experimentally, looking at the parameter space is time consuming and in most cases unfruitful. Theoretically, the same limitations exist but are easier to troubleshoot and manage. Towards this end a new more usable optical tweezers toolbox has been written. Understanding of the underlying theory has been improved, as well as the regimes of applicability of the methods available to the toolbox. Here we discus the physical principles and carry out numerical comparisons of performance of the old toolbox with the new one and the reduced (but portable) code.

3D dynamic motion of a dielectric micro-sphere within optical tweezers

“…There are two main types of approaches: namely ray optics method and electromagnetic scattering method. In terms of the computational resources and time to solve the dynamic process, the ray optics method has advantages over electromagnetic approaches such as finite-difference time-domain (FDTD) method 16 or T-matrix method 17,18 . Taking the widely used method of FDTD as an example, the simulation area is needed to be 5 μm × 5 μm × 5 μm for a 3 μm diameter micro-particle.…”