AI 中文总结
研究基于磁性石榴石薄膜磁全息图的磁光有源透镜，用永磁体阵列创建图案聚焦激光束，通过施加磁场脉冲可逆切换聚焦状态，优化后实现10.8μs切换速度，超传统有源透镜，为超快有源透镜提供概念验证。
AI 中文摘要
基于超表面的有源透镜已在广泛应用中得到证明，但其响应速度仍限于微秒级。本文报道了基于在磁性石榴石薄膜上形成的磁全息图的磁光（MO）有源透镜的实验演示。使用永磁体阵列创建菲涅耳波带片图案，将直径12.5mm的633nm激光束聚焦到3.1m焦距处的光斑尺寸为0.7mm，调制深度约为91%。通过施加外部磁场脉冲可使聚焦状态可逆切换。通过优化磁场施加系统，实现了10.8μs的切换速度，超过了传统有源透镜的工作速度。MO效应固有的皮秒级响应表明切换速度可进一步提高，为超快有源透镜提供了概念验证。
英文摘要
Active lenses based on metasurfaces have been demonstrated across broad applications, and their response speeds remain limited to the microsecond range. Here we report the experimental demonstration of a magneto-optical (MO) active lens based on a magnetic hologram formed on a magnetic garnet film. A Fresnel zone plate pattern was created using an array of permanent magnets, focusing a 633 nm laser beam of 12.5 mm diameter to a spot size of 0.7 mm at a focal length of 3.1 m with a modulation depth of ~91%. The focusing state was reversibly switched by applying an external magnetic field pulse. Through optimization of the magnetic field application system, a switching speed of 10.8 $μ$s was achieved, surpassing the operating speeds of conventional active lenses. The intrinsic picosecond-scale response of the MO effect indicates that further improvement in switching speed is achievable, establishing this work as a proof-of-concept for ultra-fast active lenses.
Comments24 pages, 4 figures; Supplementary Information: 6 pages, 3 figures
