折射率对金属-电介质-金属光子晶体强透射特性的影响

通过改变一个薄电介质层的折射率来研究其对金属-电介质-金属光子晶体(M-D-MPhC)强透射特性的影响。采用与CMOS工艺兼容技术制作了由折射率分别为nd(SU-8)=1.6,nd(SiO2.1N0.3)=1.6和nd(SiO0.6N1)=1.8]组成的三个正方形晶格圆孔阵列M-D-MPhC结构,利用傅里叶变换红外光谱仪测量其透射光谱。实验结果发现,金-SiO2.1N0.3-金结构能够获得较强的光透射增强效果和较窄的透射峰,证明了M-D-MPhC强透射特性既与中间电介质折射率大小有关,又与其材料制作工艺差异有关。采用时域有限差分(FDTD)法模拟了在相同条件下折射率分别为1.6和1.8组成的M-D-MPhC透射光谱和电场强度密度分布,模拟结果较好地符合了实验发现。

Effect of Refractive Index on Extraordinary Transmission Properties for Metal-Dielectric-Metal Photonic Crystal

The effect of refractive index on extraordinary transmission properties for metal-dielectric-metal photonic crystal (M-D-MPhC) by changing a thin dielectric layer is studied. Three M-D-MPhC structures combined with square lattice round holes array with different refractive indexes nd（SU-8）=1.6, nd（SiO2.1N0.3）=1.6 and nd（SiO0.6N1)=1.8] are fabricated using compatible technology with CMOS process, and their transmission spectra are measured using Fourier transform infrared spectrometer. It is found that Au-SiO2.1N0.3-Au structure can obtain better effect of light transmission enhancement and narrower transmission peak in experimental results. It is demonstrated that extraordinary transmission properties for M-D-MPhC depend strongly on both the size of refractive index of middle dielectric and its material fabrication process difference. The finite-difference time-domain (FDTD) method is used to simulate transmission spectra and electric field intensity density distribution of M-D-MPhC with refractive index of 1.6 and 1.8 respectively under the same conditions. Simulation results agree well with the experimental findings.