It is common to introduce optical tweezers using either geometric optics for large particles or the
Rayleigh approximation for very small particles. These approaches are successful at conveying the
key ideas behind optical tweezers in their respective regimes. However, they are insufficient for
modelling particles of intermediate size and large particles with small features. For this, a full
field approach provides greater insight into the mechanisms involved in trapping. The advances in
computational capability over the last decade have led to better modelling and understanding of
optical tweezers. Problems that were previously difficult to model computationally can now be solved
using a variety of methods on modern systems. These advances in computational power allow for full
field solutions to be visualised, leading to increased understanding of the fields and behaviour in
various scenarios. In this paper we describe the operation of optical tweezers using full field
simulati…