Controlled Formation of Optically Bound Matter in Evanescent Fields

摘要

In this paper, we detail two techniques for standing wave evanescent field optical trapping utilizing total internal reflection at a prism-water interface. Firstly, we describe an actively-locked cavity enhancement technique that generates circulating powers in excess of 10 W over an area of 150 μm x 75 μm on the prism surface using a 400 mW source, as well as providing control over the shape of the underlying transverse cavity mode. Secondly, we have combined an inverted optical tweezers with a counter-propagating evanescent wave trapping experiment, providing a useful platform for exploring light scattering interactions between small ensembles of particles. The resulting structures are compared to our theoretical model based upon Generalised Lorentz-Mie Theory.