Dynamically reconfigurable optical trap created with a combination of axicons

Abstract

The use of axicons or conical lenses has been implemented and proposed in different optical traps, either to create propagation invariant optical fields like Bessel beams or to generate other kinds of traps like hollow beams. In this work we show that the optical field emerging from a system formed by the combination of two axicons can have very different configurations and propagation properties depending upon a few relevant parameters of the system, such as the internal angles of the axicons, the distance between them and their diameters. In particular, by varying only the distance between the axicons, the emerging field may change from a single Bessel beam to a collimated hollow beam or to an array of optical bottle beams, which corresponds to the interference of two Bessel beams with different parameters. Based on these results, we propose a new dynamically reconfigurable optical trap.