Vortex-field enhancement through high-threshold geometric metasurface
通过高阈值几何超表面增强涡流场
高閾値幾何学的メタサーフェスによる渦場の強化
고임계값 기하학적 메타표면을 통한 와류장 강화
Mejora del campo de vórtices a través de una metasuperficie geométrica de umbral alto
Amélioration du champ tourbillonnaire grâce à une métasurface géométrique à seuil élevé
Улучшение вихревого поля с помощью высокопороговой геометрической метаповерхности
Qingsong Wang 王青松 ¹ ², Yao Fang 方瑶 ¹ ², Yu Meng ¹ ², Han Hao 郝涵 ¹ ² ³, Xiong Li 李雄 ¹ ² ³, Mingbo Pu 蒲明博 ¹ ² ³ ⁴, Xiaoliang Ma 马晓亮 ¹ ² ³, Xiangang Luo 罗先刚 ¹ ² ³
¹ National Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, China
中国 成都 中国科学院光场调控科学技术全国重点实验室
² State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
中国 成都 中国科学院光电技术研究所 微细加工光学技术国家重点实验室
³ College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
中国 北京 中国科学院大学材料科学与光电技术学院
⁴ Research Center on Vector Optical Fields, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
中国 成都 中国科学院光电技术研究所 矢量光场研究中心
Intense vortex beam is expected to empower captivating phenomena and applications in high power laser-matter interactions. Currently, the superposition of multiple vortex beams has shown the unique ability to tailor and enhance the vortex field.
However, traditional strategies to generate such beams suffer from large volume or/and low laser-induced damage threshold, hindering the practical widespread applications. Herein, a single high-threshold metasurface is proposed and experimentally demonstrated for the generation and superposition of multiple collinear vortex beams. This scheme takes advantage of the high conversion efficiency of phase-only modulation in the metasurface design by adopting the concept of a sliced phase pattern in the azimuthal direction.
An optical hot spot with an enhanced intensity and steady spatial propagation is experimentally achieved. Moreover, femtosecond laser-induced birefringent nanostructures embedded in silica glass are utilized as the building block with high optical efficiency. Transmittance greater than 99.4% in the near-infrared range and laser-induced damage threshold as high as 68.0 J/cm2 (at 1064 nm, 6 ns) are experimentally verified.
Considering these remarkable performances, the demonstrated high-threshold metasurface has promising applications in a host of high-power laser fields.
