Design And Property Analysis Of Optiacl Filter Based On 2-D Heterostructure Photonic Crystals

Photonic crystals, which can control the transmission of light perfectly at light wavescale, have attracted much attention because of their potentials for manufacturing highlyintegrated optical devices. In this thesis, optical filters based on 2-D heterostructurephotonic crystals were designed and their properties were analyzed using Fortranprograms and simulation package based on plane wave expansion (PWE) method andfinite-difference time-domain (FDTD) method. Our design and simulated results providesome indications for developing wave length tunable and add/drop optical filters in thefield of optical fiber communication.The transmission properties of L-type curved waveguides based on heterostructurephotonic crystals were analyzed thoroughly. The band structures of perfect optical crystalswere calculated using plane wave expansion (PWE) method and the transmission ofelectromagnetic waves in straight and L curved waveguides based on photonic crystalswere simulated using finite-difference time-domain (FDTD) method. The transmissionproperties of these waveguides have also been calculated respectively. The transmissionefficiency of L-type curved waveguide based on heterostructure photonic crystal in ourpaper has an enhancement of 6～7%, compared to the L-type curved waveguide based onhomostructure photonic crystal.The filtering properties of optical filters based on heterostructure photonic crystalwere studied. The band structures and electromagnetic wave transmission properties ofphotonic crystals including defects were discussed using PWE and FDTD. We haverealized filtering different wave length by introducing small cavities of different latticeconstants into curved waveguides based on heterostrueture photonic crystals.The wave length tunability of optical filters based on 2 D heterostructure photoniccrystals was realized in two ways: (1) By changing the refractive indices of neighboringmedium material of dot defects, a tunable range of 31 nm wave length was realized. (2)By changing the radius of relevent rods, tunable ranges of 12 nm and 22 nm wave lengthwere achieved, respectively.