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An application of deterministic aperiodic structures : Sensing with Plasmonic quasicrystals Ata Akatay July 24, 2009 Photonic Crystals - Romuald Houdré Application idea periodic media => the formation of well-defined energy gaps disordered random media => the presence of localized eigenstates with high field enhancement and Q-factors deterministic aperiodic structures => Suggest solutions in between deterministic aperiodic structures « defined by the iterations of simple mathematical rules, rooted in symbolic dynamics, prime number theory and L-system inflations » Dal Negro, L. and N. N. Feng (2007) Periodic Fibonacci quasi-periodic structures quasiperiodic singular continuous Thue–Morse and aperiodic structures absolutely continuous Rudin–Shapiro structures Dal Negro, L. and N. N. Feng (2007) Fractal Fourier spectra Fibonacci quasi-periodic structures Thue–Morse and aperiodic structures Rudin–Shapiro structures Dal Negro, L. and N. N. Feng (2007) Dal Negro, L. and N. N. Feng (2007) Aperiodic nanoparticle chain Dal Negro, L., N. N. Feng, et al. (2008) Transfer matrix approach valid within the dipole approximation The dipole equations of motion : In frequency domain : Simplifies to : where, and gives : Dal Negro, L. and N. N. Feng (2007) Analysis the integrated density of states (IDS) of the chain: participation ratio yields a quantitative measure of the localization degree of the eigenstates: Dal Negro, L. and N. N. Feng (2007) Dal Negro, L. and N. N. Feng (2007) Dal Negro, L., N. N. Feng, et al. (2008) Dal Negro, L., N. N. Feng, et al. (2008) Conclusion whispering-gallery (WG) mode microcavities low shifts of modal frequencies SP sensors, which benefit from high values of field intensities in the detection region broad resonance linewidths (low Q-factors), which is a limiting factor in the spectral resolution of such devices. deterministic aperiodic structures Can be designed for more flexible solutions References 1. 2. Dal Negro, L. and N. N. Feng (2007). "Spectral gaps and mode localization in Fibonacci chains of metal nanoparticles." Optics Express 15(22): 14396-14403. Dal Negro, L., N. N. Feng, et al. (2008). "Electromagnetic coupling and plasmon localization in deterministic aperiodic arrays." Journal of Optics aPure and Applied Optics 10(6): -.