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Summary form only given. We consider two resonant molecules (or nano-particles) located near the tip of an apertureless near-field scanning optical microscope (NSOM). The tip serves as a probe that allows us to observe the molecules and control the coupling between them. Various models are considered for the nanosized probe tip: a point-like dipole, a small dielectric sphere, and an elongated spheroidal...
Summary form only given. With the advent of scanning near-field optical microscopy (SNOM) ultrahigh-resolution optical microscopy has attracted renewed interest. Although after more than a decade the conventional mode of SNOM that uses a subwavelength aperture has bottomed out at a resolution of roughly 50 nm, an unlimited resolution could be expected in optical near-field microscopy. One of the conceptually...
Summary form only given. A single fluorescent molecule in an isotropic medium acts as a dipole radiator. In a locally heterogeneous environment the angular emission pattern is modified. Recently Novotny (1996) calculated strongly peaked angular emission when the emitter is brought in close proximity to a strong dielectric-metal gradient. We believe we present the first direct observation of this prediction;...
Summary form only given. In the contribution, we show clear evidence that photonic crystals (PC) can be used in ultrasmall integrated optics to cascade two elements, in this case a cavity and a waveguide. We use as a basis PC a triangular array of holes of period a=220-260 nm etched through an AlGaAs planar waveguide, in which we define a hexagonal cavity of side h=7a (H7 cavity), and a guide with...
Summary form only given. The transition between quantum and classical systems is usually ascribed to decoherence effects, which become increasingly important for larger size systems and tend to obscure the quantum behavior. Decoherence effects also come into play in the famous thought 'Gedanken' experiments on the wave-particle duality of matter. For example, in a double slit experiment with electrons,...
Summary form only given. Complementarity is one of the most basic principles of quantum mechanics. A quantum mechanical object, be it a photon or a massive particle, shows position (particle-like) or momentum (wave-like) attributes exclusively depending on the experimental situation. Over the years, Young's two-slit experiment has been emphasized as a good example of complementarity. We report two...
Summary form only given. There is a continuing interest in efficiently collecting spontaneous emission, for example in light-emitting diodes and optical sources for quantum communication. Many schemes for improving the efficiency with which spontaneous emission is collected involve the use of a microcavity. Spontaneous emission is typically coupled to the lowest order mode of a microcavity, the microcavity...
Summary form only given. There are a wide range of applications calling for low-loss, broad-band filters in the long-wave infrared, particularly in the atmospheric transmission windows at 3-5 /spl mu/m and 8-12 /spl mu/m. McIntosh et al. (1997) have demonstrated the use of metallo-dielectric photonic crystals (MDPCs) for infrared bandstop filters. Similar characteristics have been obtained at microwave...
Summary form only given. Resonant optics at a gas-solid interface can exhibit unprecedented sensitivity to gas-surface interactions if one restricts the gas volume that determines the optical response to very small distances to the surface. In the case of evanescent wave or surface plasmon spectroscopy the excited gas volume is limited by the depth of the wave penetration into the gas. Due to this...
Summary form only given. Four-particle correlation mediated by the Coulomb interaction has been found to play a major role in the nonlinear optical response at the semiconductor band edge at low excitation density. The attractive interaction of the excitons with opposite spins result in the formation of bound (bi-exciton) and unbound (scattered) two-exciton states. In this paper we report on the first...
Summary form only given. Using the density matrix formulation of quantum mechanics, the optically-heterodyne-detected coherent Raman scattering signal in the out-of-phase configuration, under the off-resonant condition, is given.
Summary form only given. Unlike semiconductors which facilitate the coherent propagation of electrons, photonic band gap (PBG) materials execute their novel functions through the coherent localization of photons. When a PBG material is doped with impurity atoms which have an electronic transition that lies within the gap, spontaneous emission of light from the atom is inhibited. Inside the gap, the...
Summary form only given. We study the energy transfer from a monolayer ofa donor Eu/sup 3+/ complex to a monolayer of an acceptor cyanine dye separated by a known distance. Initially measurements of the quenching of the donor emission as a function of the separation of the donor and acceptor monolayers were made, and these confirm the transfer process to be Forster-like in nature. The donor/spacer/acceptor...
Summary form only given. We have created state-selected /sup 87/Rb/sub 2/ molecules at rest in a dilute Bose-Einstein condensate of /sup 87/Rb atoms with coherent free-bound stimulated Raman transitions. The transition lineshape exhibits a resonance lineshape with an extremely narrow width as small as 1.5 kHz. As a result, we are able to measure the molecular binding energy with an unprecedented precision...
Summary form only given. For most values of magnetic field, very cold /sup 85/Rb atoms have a large negative scattering length and large loss rates from magnetic traps. The latter makes it difficult to cool the atoms low enough to achieve Bose-Einstein condensation (BBC), while the former constrains the size of a possible BEC to <100 atoms. However, we have found that near the Feshbach resonance...
Summary form only given. There has been increasing interest in optical processes using strong-coupling and induced transparency, termed electromagnetically induced transparency (EIT). Although the idea of EIT started for resonant /spl and/h-scheme (Raman scheme), the idea has now been extended to far-off resonance Raman system. We have reported the spontaneous evolution of strong-coupling through...
Summary form only given. We analyze the spatiotemporal waveform evolution of self-focused high power femtosecond pulses with a three dimensional phase-retrieval cross-correlation technique. The FWHM beam diameter evolution for 8l0-nm, 270-fs pulses propagating in sapphire due to self-focusing. Within the experimental power range, the beams shrink on propagation, and no catastrophic beam collapse was...
Summary form only given. The essence of the "strong correlation" problem is that interactions reduce the ability of electrons to move in a solid. Optical conductivity probes, over a wide range of time scales, the ability of electrons to move, and is therefore a key probe of correlated electron physics. One simple and robust feature of the conductivity is the "spectral weight,"...
Summary form only given. Standing wave laser fields produce a periodic potential for atoms, which can trap cold atoms in an ordered crystal-like structure to form an optical lattice. Optical lattices have been used as model systems in studies of quantum dynamical effects and quantum state control. More recently, it has been suggested that such lattices would provide an attractive system for performing...
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