| Photonic crystals (PCs), which have periodic varied refractive index, have the characteristics of photonic band gaps and photonic localization. PC-based devices can make photon easily to be controlled and show wide potential application. Surface plasmon polaritons (SPPs) are surface waves tending to propagate along the interface between metals and dielectrics. And SPPs can transfer optical signals beyond the diffraction limit and show stong local field on the metal surfaces. According to the properties of PCs and SPPs, an effective way to reduce the photonic devices' volume and improve the density of integration can be found by taking PCs and SPPs as information carriers. In this disseration, by taking advantage of the well-known optical principles, we have designed three SPPs-based and PC-based integrated photonic devices and further confirmed the optical properties of these devices by the finite-difference time-domain (FDTD) method, transfer matrix method (TMM) and other simulation method, respectively. Our results may provide some ways to construct novel functional optical components and integration systems of photonic network. The main work of this disseration includes the following three parts:1. Optical bistability(OB) in plasmonic nanocavities and its applicationSPPs are well known as the abilities of confining and enhancing the local optical field intensity. Taking the advantage of SPPs, OB can be realized in plasmonic nanovavity. In this part, a Fabry-Perot nanocavity is constructed by filling a piece of optical Kerr medium into the metal gap waveguides (MGWs). And the OB effects are observed in low incident power due to the strong local field of SPPs. Here, the nanocavity is constructed by a piece of GaAs layer with thickness of 30 nm and length of 300 nm. FDTD numerical simulations are performed to calculate the transmission spectra and output-input intensity relations. The results show the hysteresis loop of bistability in the case of with low incident intensity due to the enhancement of SPPs. The result implies a feasible way for constructing nanoscale optical logical gates, switches, all-optical transisitors etc. for high density integration of optical circuits.2. Continuously tunable slow light in plasmonic coupled resonator optical waveguide (CROW) and optical-time-division-multiplexing (OTDM)By filling optical active materials in two-dimensional metal rings, we construct a SPPs CROW to achieve continuously tunable slow light. It is well known that the group velocity is related to the relative variation of dielectric refractive index. So in SPPs CROW, the group velocity can be independently controlled by either the active material dispersion or dispersion from CROW geometry structure. To tune the gain strength, the varied material dispersion can lead to amplified or attenuated group velocity produced by the geometry structure, and so the continuously slow light can be obtained. We propose a structure constructed by filling a Lorentz model active material in 4 Ag-rings CROW. The tunable time delay is realized in it by tuning the gain strength. TMM is performed to calculate the transmission, dispersion relation and group index. FDTD method is performed to simulate the time evolution of input pulses to demonstrate the time delay. Based on this structure, a variable-bit-rate OTDM system in wide range of incoming bit-rates can be realized.3. CROW by photonic crystal with portion of photonic quasicrystals and its multi-channel slow light propertiesPC constructed with portion of quasiperiodic structures can realize the properties of photonic quasicrystals. CROW in this structure is designed for slow light. Here, a two-dimensional periodic triangular photonic crystal structures constructed with a portion of 12-fold symmetric photonic quasicrystals was proposed for multi-channel slow light. We perform plane wave expansion method to calculate its photonic band gaps and FDTD to demonstrate calculate the transmisson of the CROWs and property of the multi-channel slow light. |
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