Pulse Propagation and Time Reversal in Random Waveguides

Pulse Propagation and Time Reversal in Random Waveguides

Mode coupling in a random waveguide can be analyzed with asymptotic analysis based on separation of scales when the propagation distance is large compared to the size of the random inhomogeneities, which have small variance, and when the wavelength is comparable to the scale of the inhomogeneities. In this paper we study the asymptotic form of the joint distribution of the mode amplitudes at di...

Time-Reversal Superresolution in Random Waveguides

In this paper we analyze a time-reversal experiment in a random waveguide. We use asymptotic analysis based on a separation of scales technique. We derive an infinite-dimensional coupled power equation that we analyze in the high-frequency regime. We use this approximation to compute the transverse profile of the refocused field and show that randomness enhances spatial refocusing beyond the di...

Wave Propagation and Imaging in Random Waveguides

Electromagnetic Wave Propagation in Random Waveguides

Abstract. We study long range propagation of electromagnetic waves in random waveguides with rectangular cross-section and perfectly conducting boundaries. The waveguide is filled with an isotropic linear dielectric material, with randomly fluctuating electric permittivity. The fluctuations are weak, but they cause significant cumulative scattering over long distances of propagation of the wave...

Optical pulse propagation in metal nanoparticle chain waveguides

Finite-difference time-domain simulations show direct evidence of optical pulse propagation below the diffraction limit of light along linear arrays of spherical noble metal nanoparticles with group velocities up to 0.06c . The calculated dispersion relation and group velocities correlate remarkably well with predictions from a simple point-dipole model. A change in particle shape to spheroidal...