Abstract

In this work optical vortices of positive and negative topological charges are used for sensing depth differences of the order of 200nm over a testing object. Using a spatial light modulator, a vortex scanning process is done over an object with a known phase step. The behavior of the reflected vortices is analyzed, relating each result to the surface it interacted with. Major distortion of vortices occur when incidence is over the phase step, and general behavior over the scanning shows a higher sensitivity of this beam compared to a Gaussian beam.

© 2016 Optical Society of America