title: Fano coupling between Rayleigh anomaly and localized surface plasmon resonance for sensor applications.
abstract: Fano coupling between Rayleigh anomaly and localized surface plasmon resonance has been observed in diffractive grating structures consisting of aluminum nanolines deposited on the top surface of photoresist with each nanoline composed of tightly aggregated aluminum nanoparticles. Localized surface plasmon resonance is excited both in the nanoparticles and in the nanolines by differently polarized light. The surface propagation mode excited by the first- and second-order Rayleigh diffraction anomaly is strongly scattered and diffracted by the plasmonic aluminum grating structures, producing light rays in the same direction as the reflected light beam with the same spectral feature as the Rayleigh anomaly. The narrow-band diffracted and scattered light appears as sharp dips in the broad-band reflective optical extinction spectrum of plasmon resonance, which is recognized as a kind of Fano coupling. This kind of coupled mode is utilized successfully in refractive-index-sensor devices with excellent sensitivity.
authors: Institute of Information Photonics Technology and College of Applied Sciences, Beijing University of Technology, Beijing 100124, PR China.
authors: Feifei
authors: F
authors: Liu
authors: Institute of Information Photonics Technology and College of Applied Sciences, Beijing University of Technology, Beijing 100124, PR China. Electronic address: zhangxinping@bjut.edu.cn.
authors: Xinping
authors: X
authors: Zhang
mesh_terms: D000535:Aluminum / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D005947:Glucose / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D020349:Surface Plasmon Resonance; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D006046:Gold; D000535:Aluminum; D005947:Glucose
keywords: Fano coupling; Plasmon resonance; Plasmonic scattering; Rayleigh anomaly; Refractive-index sensors