We design two types of reflectors by using subwavelength high-index contrast gratings, which exhibit similar high focusing capabilities at normal incidence with a TE-polarized plane wave. One type has bars of different heights, whereas the other has bars of different depths. Both grating reflectors are designed to be approximately 22 \mu m in structural length and 10 \mu m in focal length, at an operating wavelength of 1.55 \mu m. Both achieve a full-width-half-maximum of 0.9 \mu m at the focal plane, which is fairly close to the diffraction limit. Their reflectance reach as high as 94% and 91%.

In order to couple into or out of a silicon photonic waveguide on silicon on insulator (SOI) substrate from optical fibers, we present a simple but practical method to design a grating coupler. The grating is periodic with fully etched slots; strong reflection between the fully etched grating and the waveguide is avoided by adding an antireflection interface. Theoretical coupling efficiency up to 43% is demonstrated. A taper waveguide used to link the grating and waveguide is also designed.

An optical delay line of coupled resonator optical waveguide (CROW) compensated by photonic crystal waveguide (PhCW) is proposed. In the structure, etching the periodic holes around the waveguide of the ring resonator waveguide does not increase the size of the CROW. Theoretical studies and numerical models indicate that through careful design, CROW and PhCW exhibit different group velocity dispersion (GVD) properties at a certain frequency range. Optical signal can not only be compensated in terms of GVD, but can also be delayed with longer time period. Due to the propagation mode mismatch of the two structures, optical loss becomes inevitable.

基于法布里珀罗(F-P)腔理论建立了一种简单有效的硅绝缘体(SOI)光波导损耗测量方法。该方法采用端面耦合，通过测试波导反射功率谱并利用傅里叶频谱信息，完成波导损耗的测量。推导中指出了无法直接利用反射谱F-P峰峰谷值求解损耗的限制因素。应用该方法实现了对刻蚀深度为750 nm和宽度为1200 nm的SOI脊形波导损耗的测量，表明该测量方法能够对小尺寸、低损耗波导实现较高精度的损耗测量。

散射矩阵方法是一种基于频域的研究方法。将散射矩阵方法用于亚波长周期性金属小孔结构的透射特性研究。以金属铜薄板为研究对象，薄板刻蚀方格子光子晶体空气圆孔；用洛伦兹德鲁德(Lorentz-Drude)模型来表征铜的介电常数ε；对不同的薄板厚度、周期大小和空气孔孔径的结构进行透射谱分析。并与时域有限差分方法计算所得结果相对照，二者吻合较好。仿真结果表明，如果在金属薄板上刻蚀亚波长周期性空气孔，原本不能透射光波的金属薄板将会出现异常透射现象。这是由周期性金属小孔中表面等离子波子共振导致的结果。用散射矩阵方法与时域有限差分方法分别基于频域和时域进行仿真，二者相互验证，从而可以有效地检验结果的正确性，进而减少以实验来验证时域有限有限差分仿真结果的成本，增强仿真能力。

利用单层亚波长硅光栅结构设计出工作在近红外波段的偏振分束器。该偏振分束器在45°入射角附近对TE偏振光具有很高的反射率同时对TM偏振光具有很高的透射率，其设计原理是基于亚波长光栅的泄漏模共振效应以及类布儒斯特效应。利用散射矩阵方法和时域有限差分方法对偏振分束器进行设计和分析。模拟结果显示，该偏振分束器在1390~1600 nm的波长范围内的反射与透射消光比大于100；同时该偏振分束器具有相对较大的入射角度容差，在有限尺寸高斯光束入射下能保持很好的性能。

构建了用于高性能并行计算的PC机群环境，将基于此机群环境的三维并行时域有限差分算法用于光子晶体薄板W3波导传输特性研究．性能分析表明：对于大规模问题，机群并行FDTD算法能够获得较理想的加速比．具体计算了W3波导的透射率频谱和光场分布．结果表明：光子晶体薄板W3波导能够实现光的三维约束，其导带中存在着微小禁带(mini－gap)．