文章编号：1000-5641(2023)04-0127-10亚波长铌酸锂薄膜导模共振结构设计及二次谐波转化效率优化曹春雨1,瞿敏妮2,谢微1（1.华东师范大学精密光谱科学与技术国家重点实验室,上海200241;2.上海交通大学电子信息与电气工程学院先进电子材料与器件平台,上海200240）摘要:基于亚波长铌酸锂薄膜刻蚀导模共振超表面结构,理论模拟了超表面结构的光学响应特性,探讨了刻蚀微纳结构的周期、填充因子和刻蚀深度等参量对透射光谱的影响,同时研究了不同偏振态和入射角度的光源对光谱线宽的作用;利用非对称的光栅结构设计,使连续谱中的束缚态(boundstatesinthecontinuum,BIC)衰退为高Q值(>10000)的准BIC模式;利用束缚态的局域场增强效应,将亚波长铌酸锂薄膜的二次谐波转化效率提升了5个数量级.模拟结果表明,当入射基频波的峰值功率密度在约1GW/cm2量级时,可实现紫外波段二次谐波高效转化,即单次穿过亚波长铌酸锂薄膜后,出射的紫外波段二次谐波转化效率高达10–3量级.这为提升微纳结构、光学表界面体系的非线性响应特性提供了思路和设计方案.关键词:铌酸锂薄膜;光学超表面;导模共振;二次谐波中图分类号:O437.1文献标志码:ADOI:10.3969/j.issn.1000-5641.2023.04.014SubwavelengthlithiumniobatefilmguidedmoderesonancestructuredesignandsecondharmonicconversionefficiencyoptimizationCAOChunyu1,QUMinni2,XIEWei1（1.StateKeyLaboratoryofPrecisionSpectroscopy,EastChinaNormalUniversity,Shanghai200241,China;2.CenterforAdvancedElectronicMaterialsandDevices,SchoolofElectronicsInformationandElectricalEngineering,ShanghaiJiaoTongUniversity,Shanghai200240,China）Abstract:Theopticalresponsecharacteristicsofasubwavelengthlithiumniobatefilmguided-moderesonancemetasurfacewereinvestigatedviasimulations.Theinfluencesofparameterssuchastheperiod,fillingfactorandetchingdepthoftheetchedmicro–nanostructureonthetransmissionspectrumwereexamined,andtheeffectsoflightsourceswithdifferentpolarizationstatesandincidenceanglesonthespectrallinewidthwereimvestigated.Becauseoftheasymmetricgratingstructuredesign,theboundstatesinthecontinuum(BIC)decayintoaquasi-BICmodewithahighQvalue(>10000),andthesecondharmonicconversionefficiencyofthesubwavelengthlithiumniobatefilmincreasesbyfiveordersofmagnitudeasaresultofth...
