Tunable photonic crystals enable new optical physics and devices

We show that tunable photonic band gap materials offer new opportunities for device applications. Optical switches or sensors that are far more compact and sensitive, for instance, can be constructed when we introduce either optical or mechanical tunability into photonic crystal structures. Furthermore, when we tune the photonic crystal while a photon is inside the crystal, the crystal can exhibit qualitatively different optical physics effects. As a particularly exciting example, we show that light can in fact be completely stopped in a tunable photonic crystal, and the conventional delay bandwidth product limit in resonator optics can be completely overcome.