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 and are highly dependent upon interface quality. With a nearly atomic scale surface roughness, surface-tension-induced microcavities such as lliquid 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. In this seminar I will present recent advances in demonstrating an ultra-high-Q toroid microcavity on a silicon chip, which allow observing and exploring a variety of nonlinear optical processes, such as stimulated Raman scattering, optical parametric oscillation and radiation pressure driven mechanical oscillations. These nonlinear processes can be observed at ultra-low threshold and with high efficiency. I will conclude the presentation with rareearth and silicon nanocrystal doping of toroid microcavities.

Seminar, 2nd t of September, 12.00h. Conference Room, Nexus II, 1st floor