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Summary form only given. Recently, atom manipulation by using optical near fields has been attracting a lot of interests. Optical near field can be localized in a nanometric region, being free from the diffraction limit in contrast to propagation light. The intensity distribution of optical near field decays rapidly as an exponential-like function. Because such a spatially inhomogeneous light field...
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. It is well-known that nonlinear interference effects in the resonant atom-light interaction can lead to interesting and important phenomena, such as electromagnetically induced transparency (EIT) of atomic medium, coherent population trapping, lasing without inversion, and others. Common to all these phenomena is the appearance of light-induced coherence between atomic levels,...
Summary form only given. Application of an ion trap as a frequency standard requires cooling of the ions or an accurate knowledge of the ion motion to compensate for frequency shifts due to the second-order Doppler effect. In this contribution we report on the observation of atomic coherence effects, which originate from the characteristic motion of Paul. Trapped ions and how these effects can be...
Summary form only given. The strong coupling between an atom and the light field in an optical microresonator causes a single atom to alter the transmission of the cavity significantly, allowing its continuous observation. At the same time, the strong coupling leads to novel optical forces acting on the atom. It was predicted that it should be possible to trap an atom with single intracavity photons.
Summary form only given. A simple cubic (SC) structure exhibiting a photonic band gap (PBG) was proposed by Sozuer and Haus (1993). Recently, Wada et al. (1997) reported a comparison between the FTIR transmission spectra of a pseudo-simple cubic lattice with theoretical transfer matrix results. The sample is composed of air rods with square and circular shaped rods made of silicon with the respective...
Summary form only given. We combine two existing fields of study to investigate semiconductor processes. Pump continuum-probe spectroscopy is a useful tool for monitoring excitonic processes in photoexcited semiconductors. Biexcitons, as phenomena in their own right, have been studied by other spectroscopic tools. Yet excitons are an intermediate state in the creation of biexcitons for most photo-generation...
Summary form only given. Two laser beams whose frequency difference is close, but not exactly equal, to that of a Raman resonance in a molecular medium will drive the resonance so as to establish a phased and, in effect, propagating molecular coherence. We discuss the conditions for the existence of Raman eigenvectors. These conditions are: (1) In analogy to electromagnetically induced transparency...
Summary form only given. The reciprocal relationship between time and frequency implies that a single short laser pulse has a broad spectrum. A pulse circulating inside a laser cavity or the periodic pulse train if a mode-locked laser, however, can be described as a coherent superposition of discrete laser modes. This frequency-domain comb of modes is now providing an elegant and universal solution...
Summary form only given. Ultrashort pulse laser systems are finding increasing application in optical frequency metrology and nonlinear optics which require precise control over the pulse frequency and phase. We show the stabilization of the frequency, phase and repetition rate of an ultrashort pulse train to a Fabry-Perot reference cavity using a unique combination of actuators allowing for sufficient...
Summary form only given. In optical frequency metrology, it is often necessary to precisely bridge THz frequency gaps. Optical frequency combs (OFC) are one technique that have recently attracted interest. Key characteristics of OFCs include consistency of comb line spacing, center wavelength, and comb width. Previous OFCs have been constructed by placing an electro-optic modulator inside a high-finesse...
Summary form only given. We review experiments and present new experimental results that demonstrate nonlinear polarization mode conversion in birefringent Bragg gratings, enhanced by the strong dispersion of the grating. We show that many of these experimental results can be explained using a simple intuitive NLSE model, with an effective dispersion provided by the grating. Finally, we use this NLSE...
Summary form only given. A coherent acceleration of atoms can be realized by an adiabatic sequence of Bragg reflections from an accelerating standing light wave. The arrangement of laser beams for such an acceleration is shown. The atom is illuminated by two counterpropagating laser beams. The fixed frequency of the pump laser /spl omega//sub 1/ is far detuned (/spl Delta/=/spl omega//sub 1/-/spl...
Summary form only given. The propagation of light in a dispersive medium is characterized by the group velocity /spl nu//sub g/=c(n+/spl nu//sup dn//d/spl nu/)/sup .1/ where n is the refractive index and /spl nu/ the optical frequency. Depending on the sign and magnitude of /sup dn//d/spl nu/ in the medium, the group velocity can be positive, infinite or negative. The group velocity corresponds to...
Summary form only given. When intense TW-fs-laser pulses propagate through the atmosphere, nonlinear effects like self-phase modulation (SPM), self-focusing (SF) or degenerated four-wave mixing (DFWM) cause an immense change of the temporal and spatial profile. The frequency content is changed, too. Depending on the initial beam profile, the pulse duration and other parameters like temporal chirp,...
Summary form only given. Laser cooled atoms play a critical role in modern designs of frequency standards such as atomic fountains. Recently, an elegant and efficient method of two-dimensional cooling to the vibrational ground state of a far-off resonance optical lattice has been demonstrated. This method is a variant of Raman sideband cooling based on the Raman transitions between the vibrational...
Summary form only given. Down-conversion processes can be divided into degenerate and nondegenerate. In the former case idler and signal photons are identical while in the latter they differ in frequencies and/or polarizations. It has been shown that transverse patterns in nondegenerate OPO and soliton dynamics in nondegenerate free propagation have qualitative differences from their degenerate counterparts...
Summary form only given. One of the great challenges in nonlinear optics is the establishment of reliable absolute values of optical nonlinearities. We here show that frequency-tripling in combination with cascaded second-harmonic and sum-frequency-generation is a veri efficient tool to obtain self-consistent reliable reference values for the third-order nonlinear optical susceptibility /spl chi//sup...
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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