Showing papers by "Robert W. Boyd published in 1991"
TL;DR: Gain narrowing of the Stokes spectrum is observed as the input laser power is increased, and large stochastic fluctuations are observed in theStokes output intensity.
Abstract: We have investigated the statistical properties of stimulated Brillouin scattering (SBS) in a single-mode optical fiber. Gain narrowing of the Stokes spectrum is observed as the input laser power is increased, and large stochastic fluctuations are observed in the Stokes output intensity. The experimental results can be described well by a theoretical model that includes the spontaneous nature of the initiation of SBS.
182 citations
TL;DR: The resonant optical response of a dense atomic potassium vapor under conditions such that the response is strongly influenced by local-field effects is studied.
Abstract: We have studied the resonant optical response of a dense atomic potassium vapor under conditions such that the response is strongly influenced by local-field effects. Our experimental results are in good agreement with the predictions of theory. We have also discovered a collision-induced shift of the potassium resonance lines given by \ensuremath{\Delta}${\mathrm{\ensuremath{\omega}}}_{\mathrm{c}\mathrm{o}\mathrm{l}=}$\ensuremath{\beta}N, where \ensuremath{\beta}=-5.0\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ ${\mathrm{sec}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{cm}}^{3}$ for the 4 $^{2}$${\mathit{S}}_{1/2}$\ensuremath{\leftrightarrows}4 $^{2}$${\mathit{P}}_{1/2}$ transition and where \ensuremath{\beta}=-3.0\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ ${\mathrm{sec}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{cm}}^{3}$ for the 4 $^{2}$${\mathit{S}}_{1/2}$\ensuremath{\leftrightarrows}4 $^{2}$${\mathit{S}}_{1/2}$\ensuremath{\leftrightarrows}4 $^{2}$${\mathit{P}}_{3/2}$ transition.
158 citations
TL;DR: A conical emission process that occurs when two beams of near-resonant light intersect as they pass through sodium vapor is described, ascribing the origin to a perfectly phase-matched four-wave mixing process.
Abstract: We describe a conical emission process that occurs when two beams of near-resonant light intersect as they pass through sodium vapor. The light is emitted on the surface of a circular cone that is centered on the bisector of the two applied beams and has an angular extent equal to the crossing angle of the two applied beams. We ascribe the origin of this effect to a perfectly phase-matched four-wave mixing process.
18 citations
Proceedings Article•
12 May 1991
TL;DR: In this paper, the cone angle of the two-beam-excited (TBE) conical emission was determined by the geometry of the interaction between two beams of light intersecting in sodium vapor.
Abstract: We have observed a new type of conical emission that occurs when two beams of light intersect in sodium vapor. Unlike the other forms of conical emission,1-4 for which the cone angle depends on material parameters, the cone angle of the two-beam-excited (TBE) conical emission that we observe is determined by the geometry of the interaction.
16 citations
TL;DR: In this paper, the authors observed chaotic fluctuations in the transmitted intensities of laser beams counterpropagating in Freon-113 (C2Cl3F3) and showed that the system entered the chaotic regime by means of the period-doubling route.
Abstract: We have observed chaotic fluctuations in the transmitted intensities of laser beams counterpropagating in Freon-113 (C2Cl3F3). As the input intensities are increased, the system enters the chaotic regime by means of the period-doubling route, in accordance with theoretical predictions.
6 citations
TL;DR: In this paper, the energy transfer between two nearly equal energy pulses from an alexandrite laser tuned near the 4/sup 2/S/sub 1/2/ to 4/Sup 2/P/sub 3/2)/ transition of potassium vapor was measured, and as much as 85% of the total incident energy was contained in one of the output beams.
Abstract: Energy transfer between two laser beams of comparable intensity due to their nonlinear interactions in an atomic vapor was investigated. Strong coupling occurs due to stimulated Rayleigh scattering when the frequencies of the two waves differ by the inverse of the excited-state lifetime. The energy transfer between two nearly equal energy pulses from an alexandrite laser tuned near the 4/sup 2/S/sub 1/2/ to 4/sup 2/P/sub 3/2/ transition of potassium vapor was measured. It was found that as much as 85% of the total incident energy was contained in one of the output beams. >
4 citations
TL;DR: In this article, the polarization properties of phase conjugation by degenerate four-wave mixing utilizing the 3S √ √ 4S two-photon-allowed transition of sodium were studied.
Abstract: We have studied the polarization properties of phase conjugation by degenerate four-wave mixing utilizing the 3S\ensuremath{\rightarrow}4S two-photon-allowed transition of sodium. We have observed high-fidelity vector phase conjugation (simultaneous conjugation of the optical wave front and the state of polarization) at a reflectivity of \ensuremath{\sim}1% for the case where the states of polarization of the two counterpropagating pump waves were circular and counterrotating. High-fidelity polarization conjugation with high reflectivity was obtained only when the forward pump wave was much stronger than the backward pump wave. To explain these results, it is necessary to include the effects of grating washout due to atomic motion in the theoretical analysis.
4 citations
01 Jan 1991
TL;DR: The motivation for studying chaos in nonlinear optical systems has been that studies of deterministic chaos can provide some insights into the origin of uncertainty in physics, and optical systems provide good systems in which to perform exacting studies of such effects.
Abstract: There has recently been great interest in the field of deterministic chaos. By deterministic chaos, one refers to the situation in which the output of a physical system fluctuates erratically in time, even though the system is governed by deterministic equations. It is known theoretically that chaotic behavior can occur only in nonlinear systems. We have been particularly interested in studying chaos in nonlinear optical systems.1 Our motivation for studying chaos in nonlinear optical systems has been two-fold: One is that studies of deterministic chaos can provide some insights into the origin of uncertainty in physics, and optical systems provide good systems in which to perform exacting studies of such effects. The other reason is that chaos can lead to limitations in the performance of practical optical devices. To illustrate this latter point, we consider some hypothetical optical device which was intended to provide a steady output but which instead produces the highly erratic output illustrated in Fig. 1. In order to stabilize the output of such a device, it is necessary to know whether the fluctuations which appear in the output are the result of random noise or of deterministic chaos, because the proper procedure for stabilizing the output would be different in the two cases. If the fluctuations are due to random noise, one might stabilize the output by shielding the system from its environment, whereas if these fluctuations are due to deterministic chaos one would need to decrease the magnitude of the nonlinearity in order to reduce the fluctuations.
2 citations
Proceedings Article•
12 May 1991TL;DR: In this paper, the authors report the experimental observation of deterministic chaos in the output intensities of counter-propagating laser beams as a result of their nonlinear interaction in a Brillouin-active material.
Abstract: We report the experimental observation of deterministic chaos in the output intensities of counterpropagating laser beams as a result of their nonlinear interaction in a Brillouin-active material. Several workers predicted that counter- propagating waves of the same frequency could show instabilities1 in a Brillouin-active medium and, for the case of relatively large Brillouin linewidth (i.e., the value of the ratio of the Brillouin. linewidth Γ to the Brillouin frequency shift Ω approximately equal to or greater than 0.3), the output intensities could show a period-doubling route to chaos.2