Pancharatnam–Berry Phase Driven by Electrical Restructuring of Liquid Crystal Polarization Grating Period

The ability to dynamically reconfigure photonic components is a cornerstone of next-generation optical systems. Nematic liquid crystal materials enable scalable, polarization-sensitive photonic devices for tunable, multifunctional optical platforms. An experimental and theoretical analysis of the diffraction properties of an electrically controlled polarization liquid crystal twist grating is presented here, based on the optical functional concept of the element as a combination of a retarder that provides an optical phase shift and a rotator that determines the polarization plane rotation. Here, we show that, within the operating voltage range corresponding to Mauguin condition violation, the electro–optical response of our electro–optical system is governed by two independent electrically controlled liquid crystal sublayers located within the element. This causes the ambiguity of the element diffraction properties with respect to the side of the radiation input into it. The electrical switching of the diffraction structure period from (Formula presented.) to (Formula presented.) (the liquid crystal layer thickness is 10 (Formula presented.)) is demonstrated. The device diffraction efficiency reaches 91% at a control voltage of 2.8 V. The possibility of precise electrical control of the device polarization-dependent diffraction properties makes it possible to simultaneously form two circularly polarized orthogonal coherent waves and control their intensity, which is a promising task for modern communications, lidar systems, holographic technologies, quantum computing and information processing.