71 research outputs found

    Defect-Induced Resonant Tunneling of Electromagnetic Waves Through a Polariton Gap

    Get PDF
    We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically demonstrate that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect.Comment: 5 pages, RevTe

    Statistics of transmission in one-dimensional disordered systems: universal characteristics of states in the fluctuation tails

    Get PDF
    We numerically study the distribution function of the conductance (transmission) in the one-dimensional tight-binding Anderson and periodic-on-average superlattice models in the region of fluctuation states where single parameter scaling is not valid. We show that the scaling properties of the distribution function depend upon the relation between the system's length LL and the length lsl_s determined by the integral density of states. For long enough systems, LlsL \gg l_s, the distribution can still be described within a new scaling approach based upon the ratio of the localization length llocl_{loc} and lsl_s. In an intermediate interval of the system's length LL, llocLlsl_{loc}\ll L\ll l_s, the variance of the Lyapunov exponent does not follow the predictions of the central limit theorem and this scaling becomes invalid.Comment: 22 pages, 12 eps figure

    Spectral engineering with multiple quantum well structures

    Full text link
    It is shown that it is possible to significantly modify optical spectra of Bragg multiple quantum well structures by introducing wells with different exciton energies. The reflection spectrum of the resulting structures is characterized by high contrast and tuning possibilities

    Scaling in the one-dimensional Anderson localization problem in the region of fluctuation states

    Full text link
    We numerically study the distribution function of the conductivity (transmission) in the one-dimensional tight-binding Anderson model in the region of fluctuation states. We show that while single parameter scaling in this region is not valid, the distribution can still be described within a scaling approach based upon the ratio of two fundamental quantities, the localization length, llocl_{loc}, and a new length, lsl_s, related to the integral density of states. In an intermediate interval of the system's length LL, llocLlsl_{loc}\ll L\ll l_s, the variance of the Lyapunov exponent does not follow the predictions of the central limit theorem, and may even grow with LL.Comment: Phys. Rev. Lett 90, 126601 (2003) 4 pages, 3 figure

    Scaling Properties of 1D Anderson Model with Correlated Diagonal Disorder

    Full text link
    Statistical and scaling properties of the Lyapunov exponent for a tight-binding model with the diagonal disorder described by a dichotomic process are considered near the band edge. The effect of correlations on scaling properties is discussed. It is shown that correlations lead to an additional parameter governing the validity of single parameter scaling.Comment: 5 pages, 3 figures, RevTe

    Effects of resonant tunneling in electromagnetic wave propagation through a polariton gap

    Get PDF
    We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically show that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect. Numerical Monte-Carlo simulations are used to examine properties of the electromagnetic band arising inside the polariton gap due to finite concentration of defects.Comment: 12 pages, 6 figures, RevTe

    Effects of spatial non-uniformity on laser dynamics

    Full text link
    Semiclassical equations of lasing dynamics are re-derived for a lasing medium in a cavity with a spatially non-uniform dielectric constant. It is shown that the non-uniformity causes a radiative coupling between modes of the empty cavity. This coupling results in a renormalization of self- and cross-saturation coefficients, which acquire a non-trivial dependence on the pumping intensity. Possible manifestations of these effects in random lasers are discussed.Comment: 4 pages, 1 figure, LaTex. Introduction is significantly rewritten, and the results is placed in the context of random lasin
    corecore