arXiv subjects

Bing Hu

Publications and source records attributed to Bing Hu.

38 records · Page 3Linked to original sources

arXiv2007

Singularity displacement in random speckle patterns of diffusive and localized waves: universality lost and regained

All random wave fields possess a network of phase singularities. We show that while the phase statistics within speckle patterns is generic, the statistics of the motion of phase singularities differs substantially for diffusive and localized waves. This reflects the changing wave interaction with the underlying modes of multiply-scattering systems. Universality is regained when the motion of phase singularities is charted against the phase excursion which reflects the variation of phase change across the speckle pattern. The evolution of speckle patterns can therefore be used to monitor internal motion in complex systems and to characterize the nature of wave propagation.

cond-mat.other↗

arXiv2006

Extended quasimodes within nominally localized random waveguides

We have measured the spatial and spectral dependence of the microwave field inside an open absorbing waveguide filled with randomly juxtaposed dielectric slabs in the spectral region in which the average level spacing exceeds the typical level width. Whenever lines overlap in the spectrum, the field exhibits multiple peaks within the sample. Only then is substantial energy found beyond the first half of the sample. When the spectrum throughout the sample is decomposed into a sum of Lorentzian lines plus a broad background, their central frequencies and widths are found to be essentially independent of position. Thus, this decomposition provides the electromagnetic quasimodes underlying the extended field in nominally localized samples. When the quasimodes overlap spectrally, they exhibit multiple peaks in space.

cond-mat.dis-nn↗