Phase recovery with the optical vortex microscope

Abstract

Abstract In this work we present the principles of recovering the phase shift introduced by the phase sample in an optical vortex scanning microscope. In this microscope a Gaussian beam with an embedded vortex illuminates the sample and then is imaged onto the observation plane of the microscope. When the sample interacts with the vortex beam, its internal structure is modified. In the case of a uniform phase change inside the focused vortex spot, the modification manifests itself as a rotation of the phase image. We show that using a vortex microscope setup we can obtain a high accuracy of the measured phase shift. The second advantage of our system is its very precise tracking of the vortex point.