Study On Optical Gain And Mode Coupling In 2-Dimensional Semiconductor Photonic Crystals

Due to the existence of in-plane band gap and compatibility with traditional planar fabrication method, 2-dimensional photonic crystal has drawn a lot of attention around the world. Photonic Crystals has been playing an important role in manipulating the spontaneous emission and optical gain. In addition to its application in active devices, Photonic Crystal is regarded as one of the most competitive candidates to realize planar photonic integrated circuit using point- and line-defect components.In this thesis, a set of vectorial electromagnetic computation software package was established to simulate the main properties and quantities of 2-dimensional photonic crystals, including dispersion relation, group velocity and electromagnetic modes distribution, etc. The optical gain modification by photonic crystal environment is also investigated, not only from the well-known inverse proportional relation with group velocity, but also from the electromagnetic mode distribution in photonic crystals. The complicated eigen-mode distributions lead to inhomogeneous optical gain modification in photonic crystals. The effect of limited sized photonic crystal structure on spontaneous emission is also studied. By using the significant transmission dip caused by mini-stopband formed in line-defect waveguide, the feasibility of realizing gas detector is proposed and investigated. A lot of work in this thesis project has been devoted to the fabrication of semiconductor photonic crystals. Until now, the primary EBL(electron beam lithography)on PMMA coated on Silicon wafer was completed and is being under improvement. The structure parameters and optical mask were design for further fabrication of SOI-based membrane photonic crystal. Preliminary studies on Si and SiO2 wet-etching were conducted.