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DY: Dynamik und Statistische Physik

DY 24: Nichtlineare Dynamik und Chaos II

DY 24.3: Vortrag

Freitag, 21. März 1997, 11:15–11:30, R4

Ray and wave chaos in Asymmetric Resonant Cavities — •Jens Uwe Noeckel — Max-Planck-Institut f. Physik komplexer Systeme, Bayreuther Str 40,01187 Dresdenn

Optical microcavity resonators of extremely high quality can be obtained by exploiting the "‘Whispering-Gallery"’ modes of convex dielectric spheroids or cylinders. In the ray picture, their long lifetimes are due to total internal reflection, which in rotationally symmetric resonators is violated only by an exponentially small evanescent leakage. For sufficiently strong shape deformation, however, the dominant escape mechanism is classical ray diffusion in phase space, as a consequence of the transition to chaos occuring in generic convex billiards. A semiclassical quantization that relies on a slow diffusion in action for the relevant modes allows us to predict that resonance lifetimes become frequency- independent at large (but convex) shape distortions. This is confirmed in numerical solutions of the wave equation for dielectric cylinders with asymmetric cross-sections. Also confirmed is the classically predicted directionality of emission from the resonant states. The intensity pattern is highly anisotropic, but universal for all whispering-gallery modes, depending sensitively on the classical phase space structure. The effects of dynamical localization and chaos-assisted tunneling are observed.