51 research outputs found

    Resonance Patterns in a Stadium-shaped Microcavity

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    We investigate resonance patterns in a stadium-shaped microcavity around nckR10n_ck R \simeq 10, where ncn_c is the refractive index, kk the vacuum wavenumber, and RR the radius of the circular part of the cavity. We find that the patterns of high QQ resonances can be classified, even though the classical dynamics of the stadium system is chaotic. The patterns of the high QQ resonances are consistent with the ray dynamical consideration, and appears as the stationary lasing modes with low pumping rate in the nonlinear dynamical model. All resonance patterns are presented in a finite range of kRkR.Comment: 8 pages, 9 figure

    Scarred Resonances and Steady Probability Distribution in a Chaotic Microcavity

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    We investigate scarred resonances of a stadium-shaped chaotic microcavity. It is shown that two components with different chirality of the scarring pattern are slightly rotated in opposite ways from the underlying unstable periodic orbit, when the incident angles of the scarring pattern are close to the critical angle for total internal reflection. In addition, the correspondence of emission pattern with the scarring pattern disappears when the incident angles are much larger than the critical angle. The steady probability distribution gives a consistent explanation about these interesting phenomena and makes it possible to expect the emission pattern in the latter case.Comment: 4 pages, 5 figure

    Directional interacting whispering gallery modes in coupled dielectric microdisks

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    We study the optical interaction in a coupled dielectric microdisks by investigating the splitting of resonance positions of interacting whispering gallery modes (WGMs) and their pattern change, depending on the distance between the microdisks. It is shown that the interaction between the WGMs with odd parity about y-axis becomes appreciable at a distance less than a wavelength and causes directional emissions of the resulting interacting WGMs. The directionality of the interacting WGMs can be understood in terms of an effective boundary deformation in ray dynamical analysis. We also discuss about the oscillation of the splitting when the distance is greater than a wavelength.Comment: 7 pages, 10 figure

    Antioxidant and Anti-Inflammatory Effects of Herbal Formula SC-E3 in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

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    SC-E3 is a novel herbal formula composed of five oriental medicinal herbs that are used to treat a wide range of inflammatory diseases in Korean traditional medicine. In this study, we sought to determine the effects of SC-E3 on free radical generation and inflammatory response in lipopolysaccharide- (LPS-) treated RAW 264.7 macrophages and the molecular mechanism involved. The ethanol extract of SC-E3 showed good free radical scavenging activity and inhibited LPS-induced reactive oxygen species generation. SC-E3 significantly inhibited the production of the LPS-induced inflammatory mediators, nitric oxide and prostaglandin E2, by suppressing the expressions of inducible nitric oxide synthase and cyclooxygenase-2, respectively. SC-E3 also prevented the secretion of the proinflammatory cytokines, IL-1β, TNF-α, and IL-6, and inhibited LPS-induced NF-κB activation and the mitogen-activated protein kinase (MAPK) pathway. Furthermore, SC-E3 induced the expression of heme oxygenase-1 (HO-1) by promoting the nuclear translocation and transactivation of Nrf2. Taken together, these results suggest that SC-E3 has potent antioxidant and anti-inflammatory effects and that these effects are due to the inhibitions of NF-κB and MAPK and the induction of Nrf2-mediated HO-1 expression in macrophages. These findings provide scientific evidence supporting the potential use of SC-E3 for the treatment and prevention of various inflammatory diseases

    Chaos Synchronization of delayed systems in the presence of delay time modulation

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    We investigate synchronization in the presence of delay time modulation for application to communication. We have observed that the robust synchronization is established by a common delay signal and its threshold is presented using Lyapunov exponents analysis. The influence of the delay time modulation in chaotic oscillators is also discussed.Comment: 9 pages, 6 figure

    Resonances in a circular dielectric cavity

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    We study resonance distributions in a circular dielectric cavity. It is shown that the decay-rate distribution has a peak structure and the details of the peak are consistent with the classical survival probability time distribution. We also investigate the behavior of the complex resonance positions at the small opening limit. At the large nn limit, the real part of complex resonance positions approaches the solutions with different mm of Dirichlet problem with a scale n2n^{-2} and the imaginary part goes zero as n2mn^{-2m} for TM and n2(m+1)n^{-2(m+1)} for TE polarization, where mm is the order of the resonance.Comment: 10 pages, 7 figure

    Quasiscarred Resonances in a Spiral-shaped Microcavity and Fresnel Filtering Effects(1)Current topics of quantum chaos in nanosciences, Chaos and Nonlinear Dynamics in Quantum-Mechanical and Macroscopic Systems)

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    この論文は国立情報学研究所の電子図書館事業により電子化されました。We discuss the quasiscarring phenomenon in a spiral-shaped dielectric microcavity. Unlike the scarred resonances which occur in many different chaotic systems, in the quasiscarred resonance there is no unstable periodic orbit underlying the pattern of localization. We analyze the Presnel filtering effects on the quasiscarred resonances and show that the theoretical expectation explains qualitatively the quasiscarred resonance patterns

    Lasing Modes in a Spiral-Shaped Microcavity(1)Current topics of quantum chaos in nanosciences, Chaos and Nonlinear Dynamics in Quantum-Mechanical and Macroscopic Systems)

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    この論文は国立情報学研究所の電子図書館事業により電子化されました。Lasing modes in a two-dimensional spiral-shaped microcavity are numerically studied in a nonlinear dynamical model, Schrodinger-Bloch model. The stationary lasing mode of the model is analyzed by comparing to the resonances in the corresponding passive cavity. We also investigate the quasiscarring patterns when a selective pumping is applied. We discuss the dynamical behavior of electric field intensity during the transient in the nonlinear dynamical model
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