Indium phosphide photonic integrated circuits incorporating photonic crystals

Photonic crystals are materials with a periodic and usually very strong index modulation offering crystal-like propagation characteristics for electromagnetic waves. These structures have for many years attracted much attention in the integrated photonics community, offering exciting prospects for the realization of extremely compact photonic devices and circuits.; The work presented is an investigation on possible applications of quasi-2D photonic crystals in InP-based monolithic photonic integrated circuits for optical communications, with focus on stop-band formation and slow and dispersive waveguide propagation. Initially, a theoretical assessment of band-edge propagation in line-defect photonic crystal waveguides is carried out based on calculated photonic band structures, numerical simulations and simplified analytical models. Capabilities and limitations of the line-defect waveguide filtering characteristics are discussed in detail.; The subsequent experimental assessment involved the development of a novel fabrication process to produce photonic integrated circuits incorporating deeply etched photonic crystals based on a mature integration platform. The photonic crystals consisted of lattices of air holes of diameters on the order of a few hundreds of nanometers, etched more than 2.5mum into the semiconductor material. Devices including both electrically pumped ridge waveguides and photonic crystal structures were fabricated and used for the characterization of the photonic crystal filter characteristics, including phase information. Both the fabrication technique and experimental characterization technique are explained.; Experimental results are presented demonstrating the availability of 20dB-extinction transmission stop-bands with bandwidths of tens of nanometers in structures of less than 80mum in length. Finally, results showing slow and extremely dispersive band-edge propagation are presented.