基于飞秒激光加工的高阈值高阶贝塞尔光束产生器件  

High-Order Bessel Beam Generator with High Laser-Induced Damage Threshold Fabricated by Femtosecond Laser

作　　者：张作蛟 方瑶 王青松 李雄[1,2] 蒲明博 马晓亮[1,2] 罗先刚 Zhang Zuojiao;Fang Yao;Wang Qingsong;Li Xiong;Pu Mingbo;Ma Xiaoliang;Luo Xiangang(State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,Sichuan,China;University of Chinese Academy of Sciences,Beijing 100049,China;Research Center on Vector Optical Fields,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,Sichuan,China)

机构地区：[1]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,四川成都610209 [2]中国科学院大学,北京100049 [3]中国科学院光电技术研究所矢量光场研究中心,四川成都610209

出　　处：《光学学报》2023年第13期268-276,共9页Acta Optica Sinica

基　　金：国家重点研发计划项目(2018YFA0701800);中国科学院关键技术研发团队项目(GJJSTD20210005)。

摘　　要：高阶贝塞尔光束能够携带轨道角动量,且具有无衍射特性,在粒子操控、激光微纳加工及非线性光学等领域具有重要应用价值。目前产生高阶贝塞尔光束的方式无法同时满足集成化和高功率场景的应用需求。基于飞秒激光诱导的双折射纳米光栅结构,提出一种高损伤阈值的集成化光场调控器件制备方法。通过调控纳米光栅的光轴方向和相位延迟量,在石英玻璃内部写入光轴取向空间变化的多层纳米光栅结构,制备的器件可以实现不同光场调控功能的叠加和不同工作波长的设计。基于所提方法制备了中心波长为532 nm、拓扑荷值为4的高阶贝塞尔光束产生器件。器件产生的高阶贝塞尔光束携带的轨道角动量与设计值相符,在4 m距离内光斑大小保持基本不变。器件的零几率激光损伤阈值为28.5 J/cm^(2)(6 ns),在高功率激光光束整形等领域具有极大的应用潜力。Objective The high-order Bessel beam(HOBB)is a special kind of vortex beam that carries orbital angular momentum(OAM)and shows non-diffractive and self-healing properties.Thus,HOBBs exhibit great application potential in laser micro/nanofabrication,microparticle manipulation,optical illumination,and nonlinear optics.So far,HOBBs have been generated by several methods,such as traditional optical systems,spatial light modulators,and metasurface.These methods,however,are incapable of achieving both high integrity and high laser-induced damage threshold(LIDT).Based on femtosecond laser-induced birefringent nanograting,a novel method is proposed for the fabrication of integrated optical modulation elements with high LIDT in this work.Multilayer structures with variable phase distribution embedded in silica glass enable the superposition of multiple optical modulation functions for the desired wavelength.For instance,an integrated HOBB generator is fabricated,and the optical modulation characteristics are demonstrated to be consistent with the simulation results.In addition,the LIDT of the fabricated HOBB generator is as high as 28.5 J/cm2(6 ns),which has considerable application potential for high-power laser modulation.Consequently,this method can be applied to the fabrication of further integrated optical elements with a high LIDT.Methods The laser-induced nanograting is an anisotropic structure with birefringent properties.First,the principle of geometric phase modulation is derived based on the birefringent nanograting.The birefringence characteristics of nanograting,including optical axis direction and phase retardance,can be employed to obtain the geometric phase modulation.Second,how the laser processing parameter affects the birefringence of the laser-induced nanograting in silica glass is explored.Then,two independent geometric phase optical elements(GPOEs),including a spiral phase plate(SPP)and a planar axicon,are fabricated and characterized individually.Within silica glass,a multilayer structure with spati

关 键 词：激光光场调控 高阶贝塞尔光束 集成化光学元件 飞秒激光 纳米光栅 激光损伤阈值 

分 类 号：O436[机械工程—光学工程]