Tunable polarizing reflector based on liquid crystal-clad guided-mode resonator.

This work develops a polarisation-tunable reflector that is based on a guided-mode resonant (GMR) filter with an integrated liquid-crystal (LC) polarisation rotator. The GMR filter serves as a linear polariser that strongly reflects linearly polarised light with high polarisation extinction ratio of 20:1 and sharp reflection band of ~20 nm in width. The LC polarisation rotator comprising an LC cell and quarter-wave plate can electrically control the polarisation orientation of the reflected light from the GMR. The required applied voltage for arbitrary polarisation rotation between 0° and 180° is less than 4.1 V. This dynamically tunable polarised reflector is also compact, integrable into optical circuits, and easily fabricated, showing high potential for practical and widespread applications. [ABSTRACT FROM AUTHOR]