Circular Grating Resonators
For future applications, like chip-to-chip or on-chip optical interconnects, a high physical integration density is necessary. Exploiting integrated micro-cavities leads to such highly dense and novel optical devices. The Circles of Light project deals with a specific type of integrated microcavities, namely circular grating resonators (CGR). The design of such a CGR is illustrated in Fig. 1.
- CGR consisting of concentric rings
Even at relatively low refractive index contrasts CGRs offer full two-dimensional light confinement. They can have a very small footprint of a few micrometers, which essentially corresponds to one of the smallest optical resonators. Because the volume in which the light is confined is so small, also the refractive index change which has to be induced to switch can be very small. Therefore, it is expected that the use of CGRs will enable high-speed electro-optical modulators to be built. All in all, this makes CGRs a very promising candidate for future very advanced Silicon-on-insulator (SOI) based nano-photonic devices clearly beyond state of the art in terms of functionality, size, speed, cost, and integration density.
