Photo-Aligned Ferroelectric Liquid Crystal Fork Grating-Mediated Fast Switchable Spiral Phase Contrast Imaging

Abstract

Extensive research has been devoted to spiral phase contrast imaging because of its notable capacity to enhance the edges of both phase and amplitude objects. We demonstrate a setup using ferroelectric liquid crystal (FLC) fork grating (FG) to enable switchable spiral phase contrast imaging within sub-milli-second responses. This system enables the electrical toggling between images featuring edge enhancement and those without it. The specially designed FLC FG generates a vortex beam while in a diffractive state and transmits a Gaussian beam when in a transmissive state. Using a two-step photo-alignment method, the produced FLC FG exhibits exceptional efficiency at approximately 35% and impressively rapid switching at around 307 μs. By introducing this method, we expand the potential applications of spiral phase contrast imaging, particularly in fields such as bio-sensing and photonics.