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Luminescence spectroscopy and time‐resolved measurements of CdSe/ZnS quantum dots (QDs) in 20 nm thick poly(methyl methacrylate) (PMMA) films reveal radiationless energy transfer from smaller to larger QDs. As confirmed by electron microscopy, the observed effects rely on QD aggregation. This aggregation and thus energy transfer can be inhibited by a PMMA copolymer containing carboxylic acid groups.

Abstract: We present a quantitative experimental analysis of a surface plasmon polariton (SPP) interferometer relying on elliptical Bragg mirrors. By using a leakage radiation microscope, we observe oscillation fringes with unit visibility at the two interferometer exits. We study the properties of the SPP beam splitter and determine experimentally both the norm and phase of the SPP reflection and transmission coefficients.

Considerable detoriation of the build-up of a picosecond pulse train in a passively mode-locked Nd+-glass laser by feedback of laser emission of about 10-4of the intra cavity energy is observed. A computer simulation is presented to explain this observation.

Bright colors have been observed when a metal island film is deposited on top of a silver mirror with a separating quartz layer. For spacer layer thicknesses that are varied from 0 to 140 nm, the visual appearance changes from blue/black to a series of brilliant spectrumlike colors. The sequence is repeated similarly for higher interlayer thicknesses. The phenomenon is analyzed in terms of a stratified medium theory by using TEM data and an electromagnetic model for the optical constants of the metal island film. For island films with a sufficiently high absorbance (> 0.35), the spectra are characterized by two sharp minima where the reflectivity drops to values below 10^−3. The observed thickness dependence is analyzed in terms of a complex combination of the phase shifts caused by the island film, the spacer, and the relevant interfaces.

A new two-step evaporation technique has been developed by which the particles in a silver island film grow with parallel alignment and low symmetry. In contrast with rotationally symmetric particles prepared in the usual way of island evaporation, films of such particles shown second-harmonic generation (SHG) in transmission and reflection when irradiated normally to the substrate plane. Although silver atoms arrange in a centrosymmetric crystal lattice, such specially prepared island films behave like a film of a non-centrosymmetric material. Owing to localized plasma oscillation resonances in the particles, the SH is strongly enhanced. The measured SH efficiency exceeds the SH from an α-quartz sheet of equal thickness by a factor of order 104.

We report the realization of a two-dimensional optical microscope for surface plasmons polaritons (SPPs) based on parabolic Bragg mirrors. These mirrors are built from lithographically fabricated gold nanostructures on gold thin films. We show by direct imaging by leakage radiation microscopy that the magnification power of the SPP microscope follows basic predictions of geometrical optics. Spatial resolution down to the value set by the diffraction limit is demonstrated.

The present insight into plasmon effects on the nanoscale seems sufficiently advanced to allow the development of surface-plasmon-polariton- (SPP-) based optical devices. Therefore quantitative information describing SPP phenomena is required. We investigate a SPP beam splitter constituted by silver nanoparticles on a silver thin film, fabricated by electron-beam lithography. We acquire quantitative information on the beam splitter performance by monitoring SPP leakage radiation, yielding SPP reflection, transmission, and scattering efficiencies.

Basic optical elements for surface plasmons are fabricated and their functionality (focusing, refraction, and total internal reflection) is demonstrated experimentally. The optical elements consist of dielectric structures of defined geometry on top of a gold film. The working principle of these structures is discussed on the basis of calculated surface plasmon dispersion relations.

Absorbing mirrors are optical thin film systems consisting of an absorbing metal layer held by a transparent interlayer in defined distance to a (metal) mirror layer. In the reflected light, such three-layer systems show vivid color effects due to the absorption in the metal. This absorption is modified and enhanced by interference effects. The interference condition can be tuned by the thickness of the transparent interlayer. We show by experimentation and by stratified medium model calculations the importance of a nanoscale granular structure in the absorbing metal layer for obtaining a wide spectral range of the color effect.