D. Armani et al Nature

S. Spillane et al Nature

A. Armani et al APL

L. Yang et al APL

Aoki, T et al Nature

The recent research in the Vahala Group can be broken into several sub-groups:

Ultra-High-Q toroidal microresonator: The development of the Ultra-high-Q silica toroidal microresonator has enabled many other devices such as High Q polymer resonators, four port couplers, and tunable microresonators. Additionally, recent results have shown pressure-driven mechanical oscillations present in the toroid.

Non-linear Optics: Because of the very small mode volume and the very high-Q of silica microresonators, the power build-up is extremely large. This allows for studies of non-linearities in silica which would otherwise be extremely difficult.

Sensing: Quality factors greater than 100 million in water have been achieved in water. These ultra-high-Q factors have enabled ultra-sensitive detection of heavy water heavy water.

Rare-Earth Doping: By doping silica with rare earth elements, such as erbium, microlasers are able to be fabricated. We have collaborated with Prof. Albert Polman at FOM on Er+ ion implantation.  Additionally, we have used Er+ doped sol-gel and CdSe/ZnS nanocrystals. We have collaborated with Prof. Harry Atwater at Caltech on CdSe/ZnS nanocrystal synthesis.

Cavity Quantum Electrodynamics (cavity QED): Simulations have shown that UHQ microtoroids can provide a new and useful resonator platform for cavity QED experiments. In addition, the ability to couple optical power very efficiently to and from the resonator using a tapered optical fiber will be important. We are collaborating with Prof. Jeff Kimble’s group in the Caltech Physics Department to experimentally demonstrate strong coupling between a microtoroid and a single cesium atom.