Berlin 2018 – wissenschaftliches Programm
DY 69.8: Poster
Donnerstag, 15. März 2018, 15:30–18:00, Poster A
Signatures of multiple exceptional points in optical microdisk cavities — •Julius Kullig1,2, Martina Hentschel1, and Jan Wiersig2 — 1Institut für Physik, TU Ilmenau, Ilmenau, Deutschland — 2Institut für Theoretische Physik, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Deutschland
Optical microdisk cavities can confine light for very long times in extremely small volumes. However, due to radiation and evanescent leakage the optical modes are described by the non-Hermitian dynamics of open systems. One striking signature of this non-Hermitian physics are exceptional points (EPs) in parameter space at which at least two eigenvalues (complex frequencies) as well as their corresponding eigenstates (modes) coalesce.
Exceptional points in microdisk cavities have been shown to be very useful, e.g., for sensing devices. However, in lots of experimental setups EPs are adjusted in a rather fragile way e.g., via external particles or fibre tips.
In our poster we report on EPs formed by adjusting the properties of the cavity itself such as the refractive index profile and/or the boundary shape. Furthermore, we investigate situations where not a single but several EPs occur which is beyond a two-mode scenario of a single EP2 where two modes coalesce.