Intense vortex beam is expected to empower captivating phenomena and applications in high power laser-matter interac-tions.Currently,the superposition of multiple vortex beams has shown the unique ability to tailor an...Intense vortex beam is expected to empower captivating phenomena and applications in high power laser-matter interac-tions.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-in-frared range and laser-induced damage threshold as high as 68.0 J/cm^(2)(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.展开更多
基金financial supports from the National Key Research and Development Program(Grant No.2018YFA0701800)the National Natural Science Foundation of China(NSFC)(Grant No.62192773)the West Light Foundation of Chinese Academy of Sciences(Grant No.xbzg-zdsys-202307).
文摘Intense vortex beam is expected to empower captivating phenomena and applications in high power laser-matter interac-tions.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-in-frared range and laser-induced damage threshold as high as 68.0 J/cm^(2)(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.
