Pancharatnam-Berry(PB)phase elements are widely used for optical field modulation due to their precise control over beam amplitude and phase.However,conventional PB elements are inherently static,with fixed modulation...Pancharatnam-Berry(PB)phase elements are widely used for optical field modulation due to their precise control over beam amplitude and phase.However,conventional PB elements are inherently static,with fixed modulation functions post-fabrication,limiting their adaptability in complex application scenarios.In this paper,we propose a moiré-type PB element comprising two specially designed PB elements.The proposed element attaches the two spin states with rotation-dependent PB phases while preserving the spin,thereby enabling dynamic rotation-tunability of the PB phase.As a functional validation,we experimentally demonstrate the dynamic control over the rotation rate of the polarization-rotating beam.The moiré-type PB element was designed using the checker-board-phase encoding method and fabricated in liquid crystal via SD 1-based micro-lithography.A back-propagation correction is introduced to eliminate the diffraction effects caused by the element gap.An adjustable rotation rate of±240 deg/cm is achieved through±160 deg angular offset.Owing to its compact structure with high integration and operation simplicity,the moiré-type PB element offers a novel dynamic modulation solution for structured light field generation,particle manipulation,and advanced laser processing.展开更多
基金National Key Research and Development Program of China(2022YFA1404800)National Natural Science Foundation of China(12474338,12474298,62305271,62175200,12374279,62475217)Fundamental Research Funds for the Central Universities(5110240015).
文摘Pancharatnam-Berry(PB)phase elements are widely used for optical field modulation due to their precise control over beam amplitude and phase.However,conventional PB elements are inherently static,with fixed modulation functions post-fabrication,limiting their adaptability in complex application scenarios.In this paper,we propose a moiré-type PB element comprising two specially designed PB elements.The proposed element attaches the two spin states with rotation-dependent PB phases while preserving the spin,thereby enabling dynamic rotation-tunability of the PB phase.As a functional validation,we experimentally demonstrate the dynamic control over the rotation rate of the polarization-rotating beam.The moiré-type PB element was designed using the checker-board-phase encoding method and fabricated in liquid crystal via SD 1-based micro-lithography.A back-propagation correction is introduced to eliminate the diffraction effects caused by the element gap.An adjustable rotation rate of±240 deg/cm is achieved through±160 deg angular offset.Owing to its compact structure with high integration and operation simplicity,the moiré-type PB element offers a novel dynamic modulation solution for structured light field generation,particle manipulation,and advanced laser processing.
