耦合等离激元体系的复频率分析(特邀)  

Complex Frequency Analysis of Coupled Plasmonic Systems(Invited)

作　　者：曾可博 张霜 Zeng Kebo;Zhang Shuang(New Cornerstone Science Laboratory,Department of Physics,University of Hong Kong,Hong Kong 999077,China)

机构地区：[1]香港大学物理系新基石科学实验室,中国香港999077

出　　处：《光学学报》2024年第10期301-306,共6页Acta Optica Sinica

基　　金：香港研究资助局研究基金(AoE/P-701/20,17309021)。

摘　　要：耦合等离激元体系在光场调控、光学传感、光学成像及光电器件等领域中有着广泛应用。目前,阻碍耦合等离激元进一步实用化发展的关键问题是金属材料具有较大的损耗。结合数值仿真方法,从理论上研究了耦合等离激元的损耗机理,并进一步分析复频率光源激励对耦合等离激元体系的作用,提出了通过合成复频率波的方法来补偿损耗,从而恢复被削弱的耦合共振信号。所提优化手段具有泛用性高且无需额外成本的优势,研究结果对耦合等离激元体系在各个领域中的研究发展具有借鉴意义,有利于挖掘该体系的潜在应用价值。Objective Due to the strong light-matter interactions,coupled plasmonic systems have broad applications in such areas as light manipulation,optical sensing,optical imaging,and optoelectronic devices.However,the inherent dissipation of materials and radiation dissipation of resonant structures limit the strength,service life,and propagation distance of coupled plasmonics,weakening the coupling signals and reducing the sensitivity and other performance of coupled plasmon devices.One possible solution is to add optical gain materials into the systems to compensate for the dissipation,but the utilization of gain materials is still limited because of the introduction of noise and instability.Another possibility is to employ complex frequency waves as light sources.It has been theoretically demonstrated that complex frequency waves with temporal attenuation can restore information losses.Unfortunately,producing complex frequency waves in real optical systems still faces significant challenges and has not been yielded experimentally.Currently,a novel method for synthesizing complex frequency waves has been proposed to be successfully applied to super-resolution imaging and highly sensitive biosensing.Therefore,we adopt this method to compensate for the dissipation of coupled plasmonic systems,thereby enhancing their resonance signals and avoiding experimental challenges.We hope that our study can benefit the development of coupled plasmonic systems for various potential applications.Methods We employ a periodic plasmonic structure composed of two perpendicular silver rods as an example to investigate the mechanism behind the attenuation of coupled resonance in coupled plasmonic systems.The structure is simulated by the finite-difference time-domain(FDTD)method using CST Studio Suite software.In the simulation,a plane wave with different polarization angles(45°,90°,and 135°)is normally incident onto the structure with the periodic boundary to obtain the transmission coefficients,with the permittivity of silver describ

关 键 词：物理光学 纳米光学 等离激元 复频率波 光学传感 

分 类 号：O436[机械工程—光学工程]