Kerry Vahala has pioneered nonlinear optics in high-Q optical micro resonators. His research group has launched many of the areas of study in this field and invented optical resonators that hold the record for highest optical Q on a semiconductor chip.  Vahala has applied these devices to a wide range of nonlinear phenomena and applications. This includes the first demonstration of parametric oscillation and cascaded four-wave mixing in a micro cavity - the central regeneration mechanisms for frequency micro combs; electro-optical frequency division - used in the most stable commercial K-band oscillators;  and the first observation of dynamic back action in cavity optomechanical systems. His micro-resonator devices are used at the National Institute of Standards and Technology (NIST) in chip-based optical clocks and frequency synthesizers. They have also been used at the Keck II observatory in Hawaii as miniature astrocombs in the search for exoplanets. Vahala's current research is focused on the application of high-Q optical micro resonators to miniature precision metrology systems as well as monolithic optical gyroscopes. Professor Vahala was also involved in the early effort to develop quantum-well lasers for optical communications. That work formed the basis for nearly all of today's high-speed semiconductor laser design for lightwave high-speed telecommunications, particularly in the metropolitan and local-area arena.