Generation of arbitrary optical fields using a spatial light modulator

Laser beam manipulation and shaping is an important research field for a variety of applications ranging from metrology and material processing to cell manipulation. We present a simple optical setup with a liquid-crystal-on-silicon based spatial light modulator (SLM) as the central element, to generate scalar laser beams with arbitrary optical field distributions. The applied and presented coding technique allows to calculate the required phase-only holograms, which are displayed on the SLM to shape the desired field distributions in a certain diffraction order, in real-time. We show exemplarily the efficacy of the field shaping approach by measuring the intensity of beams being coherently composed of fiber modes. Here, shaped beams are presented being characterized by well defined phase distributions and phase singularities of desired topological charge. Additionally, we introduce the ability of real-time field shaping by continuously varying modal phase differences resulting in beams with temporally rotating phase singularities.