SPECIAL EECS Seminar*

3-4 pm, Grier Rm: 36-401A

(Refreshments at 2:45)

Ultra-high-Q Optical Microcavities

Tobias Kippenberg, PhD

Optical micro-cavities confine light within dielectric volumes and are important in a variety of fields such as cavity Quantum Electrodynamics (cQED), photonics, bio-chemical sensing, and nonlinear optics. The optical trajectories occur near the interface of the dielectric cavity volume making them highly sensitive to the interface quality. With a nearly atomic scale surface roughness, surface-tension-induced microcavities such as liquid microdroplets or silica microspheres are superior to all other dielectric microresonators (e.g., photonic crystal defect cavities, micro-posts or microdisks (resonators) when their photon lifetime or the equivalent quality factor (Q) is compared.

Dr. Kippenberg will present recent advances in demonstrating an ultra-high-Q microcavity on a silicon chip. The whispering gallery modes (WGM) of these microcavities can be accessed using tapered optical fibers, which allow highly efficient coupling both to and from the WGM. The resulting high field intensity within these structures allows accessing the regime where nonlinear optical processes can be observed. In particular, stimulated Raman scattering, optical parametric oscillation and radiation pressure driven mechanical oscillations will be discussed. He will conclude the presentation with an outlook on rare-earth and silicon nanocrystal doping of toroid microcavities.