一维光子晶体带隙结构研究

Study of Band-Structure of 1-D Photonic Crystal

在考虑介质色散的基础上,研究了介质层厚度对光子晶体带隙结构的影响.利用传输矩阵法,计算了以LiF和Si两种材料组成的一维光子晶体带隙结构.结果表明,介质层厚度的增加会引起禁带的红移,厚度减小会引起蓝移.分析了含空气缺陷层、金属缺陷层的光子晶体结构,发现空气缺陷层对带隙结构的高反射区域变化不大,而在低反射区域,反射系数为零的波带之间出现了两边反射系数增加,中间反射系数减小的情况.在金属缺陷层的带隙结构中,金属对整个波长范围光的吸收作用不同,金属对低反射区1.6μm、1.85μm处透射率较大的透射光吸收作用明显,而在1.28～1.38μm处透射率波长区间,几乎无吸收.

Based on the dispersion relation,influence of the changing thickness of media to photonic crystal band structure was researched. The 1-D photonic crystal band structure made up of LiF ＆ Si was calculated by transfer matrix method. The results show that increasing or reducing the thickness of the material will bring about red shift or blue shift, and the photonic crystal band structure with air defect or metal defect was analyzed. It is found that for photonic crystal band structure with air defect, in higher reflectivity range,influence of air defect to crystal bandstructure is not significant, but in lower reflectivity range,with increase of the thickness of air defect,the reflectivity at local waveband decreases. However,at two sides of the band, the reflectivity increases for photonic crystal. In band structure with metal defect, the metal absorbs light variously across the full scope of wavelength. The metal absorbs transmission light greatly with wavelength of 1.6um and 1.85um in lower reflectivity range,but hardly absorbs transmissoion light with wavelength of 1.28-1.38um.