Microcavities, photonic bandgaps and applications to lasers and optical communications

Structures with periodically modulated refractive index are frequently discussed under the classification of photonic crystals. Recently, much attention has been paid to these types of structures for a large variety of applications such as the inhibition or enhancement of spontaneous emission, ultra-low threshold lasers, compact optical circuits, light-emitting diodes with increased efficiency and novel optical waveguides. Using structures that exhibit a photonic bandgap (PBG), it has been shown that high-Q, small modal volume microcavities can be created. Advances in semiconductor fabrication technology have made it possible to make semiconductor PBG microcavities for optical wavelengths.