Chaos-induced transparency in an ultrahigh-Q optical microcavity

TL;DR

This paper reports the experimental observation of chaos-induced transparency in an ultrahigh-Q microcavity, revealing a new interference phenomenon with tunable Fano lineshapes and potential applications in slow light and nonlinear optics.

Contribution

It introduces chaos-induced transparency in microcavities, combining chaotic and regular modes, modeled by quantum scattering theory, with high Q factors and tunable optical properties.

Findings

Demonstrated chaos-induced transparency with Q > 3×10^7

Achieved tunable Fano-like asymmetric lineshapes

Observed steep normal dispersion enabling slow light

Abstract

We demonstrate experimentally a new form of induced transparency, i.e., chaos-induced transparency, in a slightly deformed microcavity which support both continuous chaotic modes and discrete regular modes with Q factors exceeding 3X?10^7. When excited by a focused laser beam, the induced transparency in the transmission spectrum originates from the destructive interference of two parallel optical pathways: (i) directly refractive excitation of the chaotic modes, and (ii) excitation of the ultra-high-Q regular mode via chaos-assisted dynamical tunneling mechanism coupling back to the chaotic modes. By controlling the focal position of the laser beam, the induced transparency experiences a highly tunable Fano-like asymmetric lineshape. The experimental results are modeled by a quantum scattering theory and show excellent agreement. This chaos-induced transparency is accompanied by extremely steep normal dispersion, and may open up new possibilities a dramatic slow light behavior and a significant enhancement of nonlinear interactions.