Photonic crystals and photonic microstructures: technologies and device potential

My lecture will be concerned with various forms of photonic crystal, but mostly with photonic crystals created by microstructuring techniques and nanotechnology in thin, 'single-mode', optical waveguides. Because of their pre-eminent role in lasers and LEDs, the optical waveguides used for much of the work to be described are epitaxial III-V semiconductor heterostructures. Photonic crystals are interpreted as being regular structures exhibiting a large modulation of the refractive index and with periodicity in one, two or three dimensions. The emphasis in the presentation will be on gaining a physical understanding of how photonic bandgap behaviour can appear in photonic crystals, leading on to various new device concepts. Leading-edge fabrication technology, in particular direct-write electron-beam lithography (EBL) and reactive ion etching (RIE), play an essential role in realising the photonic microstructures which become photonic crystals for light in the near infrared and visible parts of the spectrum.