Efficient and monolithic polarization conversion system based on a polarization grating

摘要

We introduce a new polarization conversion system (PCS) based on a liquid-crystal polarization grating (PG) and louvered wave plate. A simple arrangement of these elements laminated between two microlens arrays results in a compact and monolithic element, with the ability to nearly completely convert un-polarized input into linearly polarized output across most of the visible bandwidth. In our first prototypes, this PG-PCS approach manifests nearly 90percent conversion efficiency of unpolarized to polarized for +-11 deg input light divergence, leading to an energy efficient picoprojector that presents high efficacy (12 lm/W) with good color uniformity.