[Todos] Seminario del Grupo de Física Teórica- Lunes 10 de Noviembre

[Alejandro M.F. Rivas]

               Seminario del Grupo de Física Teórica

                  Lunes 10 de Noviembre, 11 hs,
		Laboratorio TANDAR, Aula Sol-Sol

                     Dr. Martina Hentschel


        Emmy-Noether Group "Many-Body Effects in Mesoscopic Systems"
	  Max-Planck-Institut für Physik komplexer Systeme: Dresden

	http://www.mpipks-dresden.mpg.de/~martina/hentschelgruppe/



Título: Quantum chaos in optical microcavities: From the Goos-Haenchen shift
to non-Hamiltonian dynamics and directional light emission.


Resumen:
Optical microcavities are open billiards for light in which
electromagnetic waves can, however, be confined by total internal
reflection at dielectric boundaries. These resonators enrich the class of
model systems in the field of quantum chaos and are an ideal testing
ground for the correspondence of ray and wave dynamics that, typically, is
taken for granted. Using phase-space methods we show that this assumption
has to be corrected towards the long-wavelength limit. We show that curved
interfaces require a semiclassical correction to Fresnel's law due to an
interference effect called Goos-Haenchen shift. It is accompanied by the
so-called Fresnel filtering which, in turn, corrects Snell's law. These
two contributions are especially important near the critical angle and of
similar magnitude. Implementing both effects into the ray model improves
the agreement with wave optics by about one order of magnitude. We discuss
the phase-space dynamics of light in this amended ray-optics picture and
show that the Poincare surface of section can be significantly modified
due to the resulting non-Hamiltonian ray dynamics that implies, for
instance, the formation of attractors and repellors.
We also discuss the application-oriented problem how to achieve
directional emission from microcavity lasers. In particular, we address
experimental findings for microlasers of spiral shape and explain why
directional emission was found in numerous, but not in all cases.
Furthermore, we demonstrate that the Limacon shape robustly produces a
highly directional output that was first theoretically predicted and
subsequently observed in various experiments.