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  1. Reply to 'Comment on 'Realization of a bipolar atomic Solc filter in the cavity-QED microlaser''

    In this reply to the Comment by Bouchene et al.[Phys. Rev. A 84, 037801 (2011)], we show that our experiment [Phys. Rev. A 81, 053824 (2010)] was a legitimate demonstration of the atomic Solc filter for the range of parameters that we have studied. The more detailed theoretical framework presented in the Comment and the interpretation of its outcome in terms of nonadiabatic jump are only necessary for larger field intensities.

  2. Realization of a bipolar atomic Solc filter in the cavity-QED microlaser

    We report experimental realization of a rudimentary atomic Solc filter, recently proposed by Hong et al. [Opt. Express 17, 15455 (2009)]. It is realized by employing a bipolar atom-cavity coupling constant in the cavity-QED microlaser operating with a TEM{sub 10} mode in a strong coupling regime. The polarity flip in the coupling constant dramatically changes the photoemission probability of a two-level atom relative to unipolar coupling, resulting in multiple narrow emission bands in the detuning curve of the microlaser mean photon number. The observed resonance curves are explained well by a two-step, three-dimensional, geodesic-like motion of the Bloch vector in the semiclassical limit.

  3. Observation of multiple thresholds in the many-atom cavity QED microlaser

    We report the observation of multiple laser thresholds in the many-atom cavity QED microlaser. Traveling-wave coupling and a supersonic atom beam are used to create a well-defined atom-cavity interaction. Multiple thresholds are observed as jumps in photon number due to oscillatory gain. Although the number of intracavity atoms is large, up to N{approx}10{sup 3}, the dynamics of the microlaser agree with a single-atom theory. This agreement is supported by quantum trajectory simulations of a many-atom microlaser and a semiclassical microlaser theory. We discuss the relation of the microlaser with the micromaser and conventional lasers.

  4. Calibration of second-order correlation functions for nonstationary sources with a multistart, multistop time-to-digital converter

    A novel high-throughput second-order correlation measurement system is developed that records and makes use of all the arrival times of photons detected at both start and stop detectors. This system is suitable, particularly for a light source having a high photon flux and a long coherence time, since it is more efficient than conventional methods by an amount equal to the product of the count rate and the correlation time of the light source. We have used this system in carefully investigating the dead time effects of detectors and photon counters on the second-order correlation function in the two-detector configuration. For a nonstationary light source, a distortion of the original signal was observed at high photon flux. A systematic way of calibrating the second-order correlation function has been devised by introducing the concept of an effective dead time of the entire measurement system.

  5. Normal Mode Line Shapes for Atoms in Standing-Wave Optical Resonators

    A high finesse standing-wave cavity mode resonantly interacting with a beam of two-level {sup 138}Ba atoms is weakly driven by a tunable laser. Transmitted and sidelight scattered line shapes are recorded. With mean intracavity atomic number, {l_angle}{ital {bar N}}{r_angle}{approx_equal}1, we observe one-, two-, and three-peaked line shapes for strong coupling. In addition, two-peaked spectra observed in intermediate coupling demonstrate that line-shape splitting is not necessarily indicative of oscillatory atom-cavity energy exchange. Several atoms are required for {l_angle}{ital {bar N}}{r_angle}{approx_equal}1, so this is not a true single-atom regime. {copyright} {ital 1996 The American Physical Society.}

  6. Single atom emission in an optical resonator

    A single atom coupled to a single mode of a radiation field is a fundamental system for studying the interaction of radiation with matter. The study of such systems has come to be called cavity quantum electrodynamics (QED). Atoms coupled to a single mode of a resonator have been studied experimentally and theoretically in several interesting regimes since this basic system was first considered theoretically by Janes and Cummings. The objective of the present chapter is to provide a theoretical framework and present a unifying picture of the various phenomena which can occur in such a system. 35 refs., 11 figs.

  7. Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)

    By exploiting the extremely large effective cross sections (10{sup -17}{endash}10{sup -16}cm{sup 2}/molecule) available from surface-enhanced Raman scattering (SERS), we achieved the first observation of single molecule Raman scattering. Measured spectra of a single crystal violet molecule in aqueous colloidal silver solution using one second collection time and about 2{times}10{sup 5}W/cm{sup 2} nonresonant near-infrared excitation show a clear {open_quotes}fingerprint{close_quotes} of its Raman features between 700 and 1700cm{sup -1}. Spectra observed in a time sequence for an average of 0.6 dye molecule in the probed volume exhibited the expected Poisson distribution for actually measuring 0, 1, 2, or 3 molecules. {copyright} {ital 1997} {ital The American Physical Society}

  8. Direct measurement of velocity-changing collision cross sections by laser optical pumping

    We extend the theory of velocity-selective laser optical pumping in atomic vapors, allowing for arbitrarily rapid velocity-changing collisional rates. The results yield a simple relationship between the line-shape areas of narrow spectroscopic features present in optically pumped samples. This relationship gives directly the ground- and excited-state velocity-changing collision rates and cross sections. We use the results to analyze the data from a laser optical-pumping experiment in [sup 6]Li vapor perturbed by Ar buffer gas.

  9. Sub-doppler nuclear detection of laser-induced orientation of sup 85 Rb sup m

    Using laser-induced nuclear-orientation and optical-saturation techniques, we have produced sub-Doppler changes in the anisotropy of the angular distribution of the 514-keV {gamma} rays from the 1-{mu}s isomer {sup 85}Rb{sup {ital m}}. This permits high-resolution measurements of {ital D}1 and {ital D}2 hyperfine transitions of atoms of the isomer, which give the isomer's nuclear electric quadrupole moment, {minus}0.73{plus minus}0.17 b, and its nuclear magnetic dipole moment, (6.043{plus minus}0.005){mu}{sub {ital N}}. The isomer shift, {minus}113{plus minus}8 MHz relative to the ground state of {sup 85}Rb, corresponds to a change in the mean-square charge radius of +0.174{plus minus}0.008 fm{sup 2}.

  10. Exploration of new methods to produce efficient sources of coherent near-millimeter wave radiation. Final report, November 1982-May 1984

    A summary is presented of a feasibility study for a new concept, photon recycling, which was proposed as a new means of generating near-millimeter wave radiation using gas-dynamic cooling. A general theoretical analysis of this concept is presented which shows that small partition fractions and low temperatures lead to an unwieldly geometry for the nozzle design.


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"Dasari, R R"

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