金属光子晶体的可见光光谱特性

Optical Characteristics of Metallic Photonic Crystals

设计了一种由金属Ag和ITO(In2O3∶Sn锡掺氧化铟)薄膜呈周期排布的金属光子晶体(Metal photonic crystals,MPCs)。采用时域有限元差分法(Finite difference time domain,FDTD)计算仿真了周期和周期数对其可见光透光率和反射率的影响规律。研究表明,当金属Ag和ITO组分比一定时,随周期增加,可见光透光率曲线相应变宽,强度降低。当周期数大于4以后,可见光透光率曲线不再随周期数增加而相应变宽。随着入射角度的提高,可见光透光率曲线峰值发生蓝移,宽度相应变宽,强度相应降低。随着Ag膜层层数的增加,可见光透光率的共振峰(透射峰)相应增加。MPCs的可见光透光率峰值与反射率的峰谷具有较好的一一对应关系。

Metal photonic crystals(MPCs)consisting of periodic Ag-ITO multilayers were demonstrated in the paper.The optical transmittance and reflectance of MPCs with different cycle size and number were simulated by finite difference time domain(FDTD)method.It is found that the optical transmittance of the MPCs broadens and the intensity accordingly decreases as the cycle size increasing.For one hand,As the numbers of cycle increasing,the numbers of transmitting resonant peaks correspondingly increase,and the bandwidth of transmittance obviously broadens until the number of cycle reaching to 4.For the other hand,the location of center wavelength evidently blue shifts as the incident angle increasing.At same time,the bandwith of transmittance broadens and the intensity of that distinctly decreases.Meanwhile,the numbers of transmittance peak obviously grow up as the layers of metal films increasing.It is also demonstrated that the location of transmittance peaks and reflectance valley is one to one relationship.