极紫外波段等宽度单模狭缝波导线形波带片的聚焦分析  

Focusing Analysis of Linear Zone Plate with Equal-Width Single-Mode Slits Waveguide Working in Extreme Ultraviolet

作　　者：陈文轩 曹清[1] 程长杰 李潮越 朱吉瑞 毛亚星 Chen Wenxuan;Cao Qing;Cheng Changjie;Li Chaoyue;Zhu Jirui;Mao Yaxing(Department of Physics,College of Sciences,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学理学院物理系,上海200444

出　　处：《激光与光电子学进展》2024年第5期428-435,共8页Laser & Optoelectronics Progress

摘　　要：随着加工技术的不断进步和对空间分辨率要求的不断提高,线形波带片狭缝宽度越来越小。对于线形波带片上不同宽度的狭缝,当均匀平面波入射时,会激发一个或多个波导模,从而导致模间色散和相位差。即便只有单模传输,由于基模的有效折射率和狭缝宽度有关,不同宽度的狭缝在出射端面处也将产生相位差。为了消除这些相位差,设计等宽度单模狭缝波导线形波带片,研究其在极紫外波段的聚焦效应,并建立相应的高斯型远场解析模型。通过有限元软件的数值模拟,确认了基模的高斯型模式场分布,对基模的菲涅耳衍射积分计算则进一步确认了远场解析模型的有效性。作为一个例子,设计了一个等宽度单模狭缝波导线形波带片,并计算了其在焦平面归一化的一维光场分布。With the development of processing technology and the increasing requirement of spatial resolution,the slit widths of linear zone plate have become increasingly small.For slits with different widths on the linear zone plate,the incident uniform plane wave can excite one or more waveguide modes,resulting in inter-mode dispersion and phase differences.Even if there is only single-mode transmission in the slits,the effective refractive index of the fundamental mode is related to the width of the slit,which leads to phase difference of slits with different widths at the exit.To eliminate these phase differences,we propose an equal-width single-mode slit waveguide linear zone plate,study its focusing effect in the extreme ultraviolet band,and establish the corresponding Gaussian far-field analytical model.Numerical simulations based on finite element software confirm the distribution of the Gaussian mode field of fundamental mode,and a calculation based on the Fresnel diffraction integral further confirms the validity of the far-field analytical model.As one example,we design an equal-width single-mode slit waveguide linear zone plate and calculate its normalized one-dimensional light field distribution in the focal plane.

关 键 词：衍射 线形波带片 波导 极紫外 

分 类 号：O436[机械工程—光学工程]