Silicon Based One-Dimensional Photonic Crystal Waveguide Cavities And Its Applications

With the rapid development of information technology, the requirement of information transmission capacity and transmission rate is becoming higher and higher. Due to the “bottleneck” restrictions of the development of electronic interconnects and integrated circuits, people need a new scheme for interconnection and integration. Silicon based integrated photonics provide a platform to integrate optoelectronic devices on silicon, and realize monolithic integrated optical circuits and optical interconnects. With the advantages of high speed, low insertion loss, and compatibility with the complementary metal-oxide-semiconductor(CMOS) processes, silicon based integrated optical technology is considered to be the most promising scheme to realize interconnection and integration. One-dimensional(1-D) photonic crystal waveguide cavities, which are based on 1-D photonic crystal waveguide, can control light in nanoscale. Due to the high Q factors, ultra-small effective mode volumes, and high integrabilities with optical circuits, silicon based 1-D photonic crystal waveguide cavities are widely used in the fields of optical filters, lasers, optical sensing and nonlinear optics.In this thesis, we mainly focus on the research of silicon based 1-D photonic crystal waveguide cavities in theories and experiments. We can summarize as follows:(1) The theory of optical waveguide and 1-D photonic crystal waveguide are introduced and analyzed. The structure and several key characteristic parameters of the cavity are clarified. And the coupled mode theory of 1-D photonic crystal waveguide cavity is analyzed. In addition, several common computational methods are introduced.(2) High Q 1-D photonic crystal strip waveguide cavity based on silicon are designed to realize optical filtering in telecommunication band. Its properties of electric filed, resonance and transmission of the modes are simulated and analyzed. The process of silicon based optical devices are introduced. The fabricated 1-D cavity can possess a Lorentz filtering spectrum with a high Q factor of 64,548 and a high extinction ratio of 16 d B at resonant wavelength. In addition, tunable Fano filtering spectrums are also realized based on 1-D photonic crystal strip waveguide.(3) An optical sensor based on a 1-D photonic crystal slot nanobeam cavity are presented. A high Q factor of 1.74 × 105 and a high sensitivity around 851 nm/RIU in optical sensing can be realized in theory, which provide a new platform to realize on-chip integrated optical sensors based on silicon. Another structure of 1-D photonic crystal slot waveguide elliptical-hole cavity are designed to realize optical refractive index sensing in experiment. The device is fabricated in our lab. And the transmission spectrums of the cavity are measured.