样品连续旋转的高阶导模干涉刻写多层亚波长圆光栅  

Multi-Layer Subwavelength Circular Grating Fabricated by High-Order Waveguide Mode Interference and Continuous Sample Rotation

作　　者：苏盈文 陈振宇 徐月奇 王向贤[1] Su Yingwen;Chen Zhenyu;Xu Yueqi;Wang Xiangxian(School of Science,Lanzhou University of Technology,Lanzhou 730050,Gansu,China)

机构地区：[1]兰州理工大学理学院,甘肃兰州730050

出　　处：《激光与光电子学进展》2022年第11期374-380,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61865008);甘肃省大学生创新创业训练计划(DC2020184)。

摘　　要：提出了一种基于样品连续旋转的高阶导模干涉刻写多层亚波长圆光栅的方法。利用有限元法模拟导模干涉场,以及坐标旋转矩阵和数值模拟方法研究对样品实施连续旋转曝光后的总光场。选取442 nm波长激光作为激发光,以TE5和TM51为例,研究了高阶导模干涉刻写制备多层亚波长圆光栅的光场分布。通过光场分布分析了多层亚波长圆光栅在X-Y平面的周期以及Z轴的周期和层数,这些参数可通过改变光刻胶厚度和干涉曝光的导波模式来调节。同一厚度光刻胶条件下存在着多种高阶导模,且同阶导模对应的激发角可以通过改变光刻胶的厚度进行有效调控。因此,通过选择不同厚度的光刻胶,选取曝光所用的高阶导模,可以刻写各种不同参数的多层亚波长圆光栅。该方法是制备多层亚波长圆光栅的一种简单而有效的方法,在微纳光学领域具有一定的应用前景。A method of fabricating the multilayer subwavelength circular gratings is proposed,which is based on the highorder waveguide mode interference and continuous sample rotation.The waveguide mode interference field is simulated by the finite element method,and the coordinate rotation matrix and the numerical simulation method are used to study the total optical field after performing continuous rotating exposure to the sample.A 442-nm laser is selected as the excitation light and TE5 and TM51 are taken as the examples to study the optical field distribution of the multilayer subwavelength circular gratings fabricated by the highorder waveguide mode interference.By the optical filed distribution,the period of the XY plane and the period and layers of the Zaxis of the multilayer subwavelength circular gratings are analyzed,which can be adjusted by changing the thicknesses of the photoresists and the waveguide modes for interference exposure.Under the condition of the same thickness of photoresist,there are many highorder waveguide modes and the excitation angle corresponding to the same highorder waveguide mode can be effectively controlled by changing the thicknesses of photoresists.As a result,the multilayer circular gratings with different parameters can be fabricated by selecting the photoresists of different thicknesses and the highorder waveguide modes used in exposure.The proposed method is a simple and effective way to fabricate the multilayer subwavelength circular gratings and has a certain application prospect in the field of micronano optics.

关 键 词：光学设计与制造 微纳光刻 高阶导模干涉 多层亚波长圆光栅 

分 类 号：O436.1[机械工程—光学工程]