| The goal of the work throughout this thesis is to develop two-dimensional photonic crystal micro/nanocavity lasers to meet all the five requirements for practical onchip sources. They are (1) electrical injection, (2) continuous-wave operation at room temperature and above, (3) sufficient in-plane output power, (4) high modulation bandwidth and low noise and (5) an integration platform.;Chapter 1 discussed the five requirements.;Chapter 2 worked out the third requirement: sufficient laser output power was collected under pulsed operations.;Chapter 3 picked quantum well intermixing as a solution to the fifth requirement and worked out the fabrication.;Chapter 4 worked out the fifth requirement by integrating photonic crystal nanocavity laser with the intermixing approach.;Chapter 5 worked out a high-performance laser-waveguide coupling design using the intermixing platform.;Chapter 6 obtained the gain compression factor and thermal resistance of a room-temperature continuous-wave laser on sapphire. Gain compression is a limiting factor for modulation bandwidth in the fourth requirement; thermal resistance is the key parameter for the second requirement.;Chapter 7 analyzed the symmetry properties in two-dimensional photonic crystal waveguides. This analysis explains the modes in Type B photonic crystal structure which may lead to high-quality-factor on-substrate designs that can fulfill all the requirements.;Appendix A calculated the surface states in the Gamma-M direction of the triangular photonic crystal lattice in the membrane structure. The understanding of the surface modes is helpful to the design of lattice termination at device junctions and boundaries.;Appendix B showed the application of digital image processing in nano-fabrication. Fabrication imperfections can be quantified by analyzing the SEM images. Sub-pixel alignment is achieved in electron-beam-lithography using correlation techniques.;Appendix C summarized the fabrication recipes. |
