Computing Liquid-Crystal Photonics Platform Enabled Wavefront Sensing

Detecting the wavefront of photons in an efficient and accurate way is crucial to retrieve the information of an optical field. Liquid crystal (LC) possesses strong ability to manipulate the phase and polarization of photons with high diffraction efficiency and therefore offers a promising avenue toward this aim. In this paper, LC performing analog optical processing is explored and a computing LC platform is proposed to implement the wavefront sensing via tuned bias retardation. It is demonstrated that precisely introducing a tiny Pancharatnam-Berry phase by LC can achieve flexible separation of two spin components with high resolution. Modulating the retardation by rotation of an analyzer, the computing LC platform is used to reconstruct wavefronts with phase-contrast patterns. In particular, combining this scheme with microscopy can precisely retrieve a micro-scale phase distribution. The result suggests that the computing LC platform can perform as a wavefront sensor with high efficiency and may open up new opportunities in the applications of precision metrology, real-time analog optical processing, and high-contrast microscopy.