High-Speed and Continuously Tunable Polarization Rotator Using High-Tilt Electrically Suppressed Helix Ferroelectric Liquid Crystals

Abstract

The dynamic control of light polarization is crucial for advancing optical and photonic technologies; however, existing polarization rotators often face a performance trade-off among speed, precision, power efficiency, and system complexity. Liquid crystal-based solutions, while advantageous in cost and integrability, are typically limited by millisecond-scale response times. In this work, we overcome these limitations by introducing a high-performance polarization rotator based on a high-tilt electrically suppressed helix ferroelectric liquid crystal (HT-ESHFLC). The device features a simple single-cell structure yet achieves continuous polarization rotation with a high degree of polarization (>97%), a wide tuning range (82°), microsecond-scale switching, and ultra-low power consumption. This performance is attributed to our tailored FLC material with chiral sematic C phase, which exhibits a long pitch, high tilt angle, and large spontaneous polarization. These properties collectively overcome the longstanding challenge of stable phase modulation in conventional deformed-helix FLC (DHFLC) and in binary working principles of ESHFLC devices. We delineate the design strategy, tracing the evolution from nematic and conventional DHFLCs to our novel HT-ESHFLC platform. To demonstrate its practical utility, we integrated the rotator with a Pancharatnam-Berry lens to construct a dynamic augmented reality display capable of rapid intensity modulation between two planes. This work establishes the HT-ESHFLC as a compelling platform for high-speed, low-power polarization modulation, with promising applications in optical communications, LiDAR, and next-generation displays.