Speckle Statistics of Localized Waves in Random Media

The onset of single-channel transport in multi-channel disordered systems due to Anderson localization is observed in speckle pattern statistics. These statistics have been gathered with microwave radiation transmitted through an ensemble of quasi-1D random dielectric samples of length two times the localization length. In a single-channel regime, the transmission speckle pattern exhibits a ``perfect memory'' effect: A shift in the direction and/or polarization of the incoming wave leaves nearly unchanged the positions and relative brightness's of speckles, while leading to large fluctuations of total transmission. The probability distribution of single-channel microwave transmittance (conductance) as determined from the measurements of speckle intensity statistics is compared to those predicted for localized waves.