用等效膜理论分析一维光子晶体的禁带特征

Analysis the properties of forbidden bands in one-dimensional photonic crystal with equivalent-layer theory

论述了等效膜理论和等效折射率概念,并通过数值计算得出了有限周期一维光子晶体的等效折射率随频率的变化。结果表明:在光子禁带等效折射率不存在,在光子禁带两边等效折射率分别趋于无穷大或者零;在光子透射带,等效折射率是有限值。此外,还用等效折射率的不连续特点,讨论了在不同结构的一维光子晶体中禁带发生位置的变化。

The concept of equivalentlayer theory and equivalent refractive index were described. The numerical calculation of equivalent refractive index variety with frequency in finiteperiod onedimensional photonic crystal has been done.The results indicated that the equivalent refractive indexes are not existence in photonic forbidden bands and in both sides of forbidden bands.The equivalent refractive indexes tend to infinity or zero.The equivalent refractive indexes are finite values in pass bands.The forbidden bands places in different structures of onedimensional photonic crystals were discussed with the unconnected character of equivalent refractive indexes.