Two-dimensional Photonic Crystal Waveguide Output Light Cluster And The Deflection Of The Relevant Studies

As new-fashioned synthetic optical material, photonic crystals (PCs) has been a focus of the recent research on optical and electromagnetic wave. PCs can control the propagation of light for its band gap structure. Therefore, PC waveguides can be fabricated in wavelength scale, and can realize many functions that the original optical devices cannot. However, as sub-wavelength structure, because of the diffraction limitation, the emitting light of PC waveguides will scatter into all directions, so the spatial control of electromagnetic emission from PC waveguides is important for the opening up of photonic crystal devices. Based on two considering, adding point defects and optimize the surface structure, this article discuss the phenomenon and method of beaming and deflection emission from a 2D PC waveguide, which are realized through cavities or surface wave. After that, we compare these two mechanisms with their advances and limits, give the optimizing projects, and give the simulation results of our designs by computer. In the last chapter, we design a new type triangle-cell-grating structure. This unsymmetrical grating structure can realize the deflection and directivity beaming of light emitting from a PC waveguide in a possible small scale, by coupling the PC surface wave into the free space and modulating the emission field of PC waveguides.