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Summary form only given. The modern development of quantum optics began with the realization that the coherence properties and most of the statistical properties of light are determined by a succession of correlation functions for the quantized electromagnetic field. Many of the cold-atom experiments of the past decade that are part of the foundation of the new field of atom optics have close optical...
Summary form only given. The squeezing of an optical field is normally observed in the frequency domain using balanced homodyne detection to measure the fluctuation variance of a selected quadrature amplitude. The scheme amounts to a measurement of sub-Poissonian photon statistics and is sensitive to efficiencies as any such unconditional measurement is. Conditional measurements are independent of...
Summary form only given. We present data that moves beyond this paradigm by exploring both spectral/spatial correlations between eigenstates of a disordered quantum well and examining spatial properties of the eigenstate itself. Unlike earlier work which relied on spectral and spatial diffusion for signal, degenerate cw nonlinear spectroscopy is utilized as an 'absorption-like' probe capable of mapping...
Summary form only given. We present a novel method for the characterization of quantization energy fluctuations in single semiconductor quantum wires (QWRs). The method takes advantage of a recently developed femtosecond near-field scanning optical microscope (NSOM). We demonstrate that the shape of degenerate near-field pump-probe traces sensitively depends on the detuning between the laser photon...
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 any optical system, quantum and classical theory yield identical predictions for the mean intensity. The quantum mechanical predictions diverge from the classical theory only for higher order correlations. For this reason, typical quantum-interference experiments are performed by measuring coincidence rates between two or more detectors. The usual approximation, following...
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. Recently, modulational instability (MI) in periodic structures has attracted considerable attention. We study MI in a bulk nonlinear medium with a Bragg grating along the direction of propagation. In these structures, MI is caused by mutual interplay among dispersion, diffraction and nonlinear effects and results in spatial and temporal effects simultaneously. Light propagation...
Summary form only given. Passive optical limiters are used to protect human eyes or sensitive optical elements from laser damage. Excited-state absorption (ESA) evoked transitions from one excited state to a higher one is a prerequisite for efficient optical limiting. Numerous parameters of the system as well as laser pulse characteristics make it difficult to determine optimum conditions for efficient...
Summary form only given. Several measurement methods of nonlinear optical Kerr coefficient n/sub 2/ in optical fibers have recently been proposed, bringing into evidence the different contributions of the electronic and electrostrictive parts, respectively n/sub 2k/ and n/sub 2e/, where electrostriction plays an important role at optical modulation frequency lower than 1.5 GHz, and is intrinsically...
Summary form only given. In a recent paper, A.V. Bragas et al. (1998) have shown a giant optical field enhancement (more than 1000) at the tip-sample junction of a scanning tunneling microscope. The magnitude of the field enhancement obtained is larger than expected from abundant calculation performed for different tip-sample geometries. In this work it is shown that when the metallic tip is approached...
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. Exciton wavefunctions are sensitive to the confinement by sample surfaces, which makes the optical response of a slab very different from that of the infinitely extended medium. This complicated coupling between microscopic exciton polarization and macroscopic optical field has led to a variety of theoretical approaches over 40 years, which either start from a macroscopic...
Summary form only given. In integrated optics, waveguides which have highly controllable dispersion while being leak-free would be very useful indeed when making optical interconnections and regions above or below the film. We present a rigorous method for investigating these modes, which are not merely strongly guided; they are true guided modes. We have developed an accurate and generally applicable...
Summary form only given. Utilizing cold and trapped atoms for precision spectroscopy of weak atomic transitions has two important advantages: the suppression of Doppler and time-of-flight broadenings and a combination of long interaction times, weak perturbations and tight confinement, which can be obtained using dark optical traps. We present a new and extremely sensitive method for measuring weak...
Summary form only given. Just as optical waveguides play a central role in many aspects of modern optics, from communications to integrated optics, atom waveguides are likely to be an enabling technology for future atom-optics-based science. In particular, well-characterized atom waveguides may make possible inertial and rotation measurements of exquisite sensitivity via large-enclosed-area atom interferometers...
Summary form only given. We present a novel technique in cavity ringdown spectroscopy that permits 1/spl times/10/sup -10/ absorption sensitivity with microwatt level light power. Heterodyne detection is employed between two alternating cavity modes, with one of them interacting with a molecular resonance.
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