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
低渗透油田开发面临传统采油技术效率低、环境污染等挑战,生物酶化学驱油技术因其环保高效而备受关注,但其在低渗透油田中的适用性和稳定性尚需进一步研究。针对这些问题展开系统性的实验研究,首先通过对不同种类生物酶的优选,发现脂肪...低渗透油田开发面临传统采油技术效率低、环境污染等挑战,生物酶化学驱油技术因其环保高效而备受关注,但其在低渗透油田中的适用性和稳定性尚需进一步研究。针对这些问题展开系统性的实验研究,首先通过对不同种类生物酶的优选,发现脂肪酶在不同质量浓度下表现出最显著的驱油效果,最佳质量浓度为2.0 g·L^(-1),可提高原油采收率至24.5%。其次,评价脂肪酶在高盐度和碱性条件下的稳定性,发现在适当质量浓度下脂肪酶仍能保持较高的驱油效果,但在极端条件下其活性可能会受到抑制。最后,研究发现脂肪酶能够有效降低原油表面张力,当质量浓度为2.0 g·L^(-1)时,原油表面张力可降至37.9 m N·m^(-1)。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.
文摘低渗透油田开发面临传统采油技术效率低、环境污染等挑战,生物酶化学驱油技术因其环保高效而备受关注,但其在低渗透油田中的适用性和稳定性尚需进一步研究。针对这些问题展开系统性的实验研究,首先通过对不同种类生物酶的优选,发现脂肪酶在不同质量浓度下表现出最显著的驱油效果,最佳质量浓度为2.0 g·L^(-1),可提高原油采收率至24.5%。其次,评价脂肪酶在高盐度和碱性条件下的稳定性,发现在适当质量浓度下脂肪酶仍能保持较高的驱油效果,但在极端条件下其活性可能会受到抑制。最后,研究发现脂肪酶能够有效降低原油表面张力,当质量浓度为2.0 g·L^(-1)时,原油表面张力可降至37.9 m N·m^(-1)。
