On the Experimental Estimation of Surface Enhanced Raman Scattering (SERS) Cross Sections by Vibrational Pumping

We present an in-depth analysis of the experimental estimation of cross sections in Surface Enhanced Raman Scattering (SERS) by vibrational pumping. The paper highlights the advantages and disadvantages of the technique, pinpoints the main aspects and limitations, and provides the underlying physical concepts to interpret the experimental results. Examples for several commonly used SERS probes are given, and a discussion on future possible developments is also presented.Comment: To be submitted to J. Phys. Chem.

Enhancement factor distribution around a single SERS Hot-spot and its relation to Single Molecule detection

We provide the theoretical framework to understand the phenomenology and statistics of single-molecule (SM) signals arising in Surface-Enhanced Raman Scattering (SERS) under the presence of so-called electromagnetic hot-spots (HS's). We show that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of tail-like (power law) distribution of enhancements and we propose a specific model for it. We analyze, in the light of this, the phenomenology of SM-SERS and show how the different experimental manifestations of the effect reported in the literature can be analyzed and understood under a unified ``universal'' framework with a minimum set of parameters.Comment: 13 pages, 4 figures, submitted to J. Chem. Phy

Surface plasmon lifetime in metal nanoshells

The lifetime of localized surface plasmon plays an important role in many aspects of plasmonics and its applications. In small metal nanostructures, the dominant mechanism restricting plasmon lifetime is size-dependent Landau damping. We performed quantum-mechanical calculations of Landau damping for the bright surface plasmon mode in a metal nanoshell. In contrast to the conventional model based on the electron surface scattering, we found that the damping rate decreases as the nanoshell thickness is reduced. The origin of this behavior is traced to the spatial distribution of plasmon local field inside the metal shell. We also found that, due to interference of electron scattering amplitudes from nanoshell's two metal surfaces, the damping rate exhibits pronounced quantum beats with changing shell thickness.Comment: 9 pages, 4 Figure

Beam focusing in reflections from flat subwavelength diffraction gratings

We predict that narrow beams, reflecting from flat subwavelength diffraction gratings, can focus. The effect is shown for the beams of electromagnetic radiation; however, it should be observable for beams of waves of arbitrary nature (microwaves, surface plasmons, and acoustic and mechanical waves). We present analytical estimations of the focusing performance obtained by multiple scattering calculations and demonstrate the focusing effect numerically for an optical system (reflections from an array of dielectric cylinders), using the finite-difference time-domain calculations.The work is financially supported by Spanish Ministerio de Educacion y Ciencia and European FEDER through projects FIS2011-29734-C02-01 and -02.Cheng, YC.; Redondo, J.; Staliünas, K. (2014). Beam focusing in reflections from flat subwavelength diffraction gratings. Physical Review A. 89(3):33814-33819. https://doi.org/10.1103/PhysRevA.89.033814S3381433819893Ghaemi, H. F., Thio, T., Grupp, D. E., Ebbesen, T. W., & Lezec, H. J. (1998). Surface plasmons enhance optical transmission through subwavelength holes. Physical Review B, 58(11), 6779-6782. doi:10.1103/physrevb.58.6779Ramos-Mendieta, F., & Halevi, P. (1999). Surface electromagnetic waves in two-dimensional photonic crystals: Effect of the position of the surface plane. Physical Review B, 59(23), 15112-15120. doi:10.1103/physrevb.59.15112Brückner, F., Friedrich, D., Clausnitzer, T., Britzger, M., Burmeister, O., Danzmann, K., … Schnabel, R. (2010). Realization of a Monolithic High-Reflectivity Cavity Mirror from a Single Silicon Crystal. Physical Review Letters, 104(16). doi:10.1103/physrevlett.104.163903Verslegers, L., Catrysse, P. B., Yu, Z., White, J. S., Barnard, E. S., Brongersma, M. L., & Fan, S. (2009). Planar Lenses Based on Nanoscale Slit Arrays in a Metallic Film. Nano Letters, 9(1), 235-238. doi:10.1021/nl802830yFattal, D., Li, J., Peng, Z., Fiorentino, M., & Beausoleil, R. G. (2010). Flat dielectric grating reflectors with focusing abilities. Nature Photonics, 4(7), 466-470. doi:10.1038/nphoton.2010.116Van de Hulst, H. C., & Twersky, V. (1957). Light Scattering by Small Particles. Physics Today, 10(12), 28-30. doi:10.1063/1.3060205Tassin, P., Van der Sande, G., Veretennicoff, I., Kockaert, P., & Tlidi, M. (2009). Pattern formation without diffraction matching in optical parametric oscillators with a metamaterial. Optics Express, 17(11), 9428. doi:10.1364/oe.17.009428Iliew, R., Etrich, C., Pertsch, T., Lederer, F., & Staliunas, K. (2008). Subdiffractive all-photonic crystal Fabry-Perot resonators. Optics Letters, 33(22), 2695. doi:10.1364/ol.33.002695Staliunas, K., Egorov, O., Kivshar, Y. S., & Lederer, F. (2008). Bloch Cavity Solitons in Nonlinear Resonators with Intracavity Photonic Crystals. Physical Review Letters, 101(15). doi:10.1103/physrevlett.101.153903Cheng, Y. C., Peckus, M., Kicas, S., Trull, J., Cojocaru, C., Vilaseca, R., … Staliunas, K. (2013). Beam focusing in reflection from flat chirped mirrors. Physical Review A, 87(4). doi:10.1103/physreva.87.04580