Reflectance Fluctuations in an Absorbing Random Waveguide

Abstract

We study the statistics of the reflectance (the ratio of reflected and incident intensities) of an $N$-mode disordered waveguide with weak absorption $\gamma$ per mean free path. Two distinct regimes are identified. The regime $\gamma N^2\gg 1$ shows universal fluctuations. With increasing length $L$ of the waveguide, the variance of the reflectance changes from the value $2/15N^2$, characteristic for universal conductance fluctuations in disordered wires, to another value $1/8N^2$, characteristic for chaotic cavities. The weak-localization correction to the average reflectance performs a similar crossover from the value $1/3N$ to $1/4N$. In the regime $\gamma N^2\ll 1$, the large-$L$ distribution of the reflectance $R$ becomes very wide and asymmetric, $P(R)\propto (1-R{)}^{-2}$ for $R\ll 1-\gamma N$.

7 pages, RevTeX, 2 postscript figures

References in corpus (3)

• Mesoscopic Transport Through Ballistic Cavities: A Random S-Matrix Theory Approach
• Probability of Reflection by a Random Laser
• Semiclassical analysis of the quantum interference corrections to the conductance of mesoscopic systems

Cited by in corpus (5)

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• Transmission through a many-channel random waveguide with absorption
• Induced vs Spontaneous Breakdown of S-matrix Unitarity: Probability of No Return in Quantum Chaotic and Disordered Systems
• Disordered Josephson junction chains: Anderson localization of normal modes and impedance fluctuations
• Signatures of Classical Diffusion in Quantum Fluctuations of 2D Chaotic Systems