Photonic crystal devices for photonic integrated circuits

Photonic crystal devices are potential candidates for chip-scale, dense photonic integrated circuits because photonic crystal devices have versatile optical characteristics and compact size. This thesis presents works to understand the properties of isolated photonic crystal elements before implement photonic integrated circuits with these individual elements as components.; In this thesis, a brief introduction for photonic crystals will be followed by a chapter describes the nanometer-scale fabrication techniques used in the formation of photonic crystal devices. It includes the expitial structure of the wafers, electron-beam lithography, dry etching techniques and other process steps in the clean room.; Photonic crystal waveguides is the main topic for the first half of this thesis. Chapter 3 will give an introduction to photonic crystal slab waveguides, include the calculated band structure and measured transmission spectra of the straight single line defect photonic crystal waveguides. We also evaluated the group indices of the waveguide bands from the measured transmission spectra. In chapter 4, photonic crystal Mach-Zehnder interferometers are demonstrated with the idea of asymmetric Mach-Zehnder structures formed in photonic crystal waveguides. Chapter 5 shows the work to characterize the reflectance of waveguide bends in photonic crystal waveguides. The low reflectance of a photonic crystal waveguide bend was obtained in a wavelength region which finite element method predicted.; The second half of the thesis presented work on the photonic crystal laser cavities. In chapter 6, sapphire-bonded photonic crystal laser cavities were demonstrated under continuous-wave pumping conditions at room temperature. The characterization of lasing modes of the cavities was by comparing the measured spectra with three-dimensional finite-difference time-domain simulation results. An experiment to characterize the optical loss of these sapphire-bonded photonic crystal cavities was also exhibited. A high quality factor photonic crystal double-heterostructure cavity was designed and demonstrated in photonic crystal waveguides. This cavity has potential to be electrically-pumped and integrated with waveguides in the same element.