Novel devices based on photonic band gap microcavities

Marin Soljacic MIT

Abstract: Photonic crystals (PhCs) enable microcavities that can have very large life-times, at the same time as having very small modal volumes. These unique features enable a range of novel applications, which will be presented in the current talk. For example, they provide excellent geometrical properties for structural enhancement of optical non-linear effects. In this manner, we will show a class of all-optical signal processing devices (based on optical bistability in non-linear PhC microcavities) of optimal performance characteristics. Lengths of these devices can be smaller than the wavelength of light, they can operate with only ~mW of power, and can be faster than 10ps, while being implemented in common materials (e.g. AlGaAs, Si). If such supreme structural enhancement of non-linearities is combined with a material of extreme non-linear response, like Electromagnetically Induced Transparency (EIT), devices of unprecedented optical non-linear response are enabled. We will show how this approach could lead to observation of non-linear phenomena at single photon energy levels. Moreover, placing material as strongly dispersive as EIT into a cavity greatly enhances its life-time; we will thus also show how this mechanism could be explored to design microcavities of extremely long life-times.