ABSTRACT
The smart use of light in science and technology is at the core of an impressive number of high-performance photonic devices ranging from laser chips and optical sensors to alloptical communication systems for high-speed computing and data transfer.1 Such functionality is achieved because of an extensive use of optical microcavities in various geometries involving coupling of one or several cavities to a waveguide. The optical response of waveguide-cavity systems can be made tunable by adding some cavities with nonlinear response or by using an external control. Microcavities also exhibit high-quality resonances, and they are used for optical modulation and switching. The on/off switching functionality is realized by shifting the resonant frequency either toward or away from the signal frequency.
