Optical vortex trajectory as a merit function for spatial light modulator correction.

Highlights • Most of the correction methods use visual inspection as a beam quality merit function. • Visual beam inspection is not sufficient when precise SLM application is needed. • Two quality criteria, based on more objective methods are proposed. • Detection of small deviation from ideal beam is possible. • Both can be applied in any system, where the beam intensity is recorded. Abstract Spatial light modulator (SLM) is a modern device extensively used for laser beam shaping. Over the years, its quality has been significantly improved. Nevertheless, there is still a need to correct its imperfections. In this paper we propose two criteria which allow to examine correction effectiveness of SLM. One is based on the Laguerre–Gauss transform and the second uses optical vortex dynamics which exposes a high sensitivity to any beam imperfections. It is based on the vortex internal scanning method, where the shape of vortex trajectory provides information about SLM correction quality. In this paper we test its sensitivity to astigmatism, which was introduced manually by SLM, after proper correction. [ABSTRACT FROM AUTHOR]