一种光子晶体开放腔的特性研究

Performance study on an open photonic crystal cavity

为了研究光子晶体开放腔特性,采用平面波展开法和时域有限差分法对顶角为30°楔角的光子晶体和空气槽交替组成的新型光子晶体开放腔进行了研究。研究发现,这种结构的光子晶体开放腔在两个归一化频率范围(0.3006～0.35,0.6755～0.6851)内具有负折射特性,并且在负折射频率范围内可形成一个零光程的闭合回路;光子晶体与空气槽的分界面上有高的透射率,能够在某个波长产生共振。结果表明,可以利用共振波长随着折射率的变化而变化的光子晶体开放腔实现折射率的高灵敏度测量。

To study the property of an open photonic crystal cavity, the new open cavity, formed by 30~ vertex angle of the photonic crystal and air tank alternately was analyzed based on the plane wave expansion method and finite-difference time-domain method. It was found that the open cavity structure had negative refraction property in both the normalized frequency bands （0. 3006 ~0. 35 and 0. 6755 -0. 6851 ）, and a zero-optical path closed-loop could be formed with the air tank in the frequency range of negative refraction; and there was a high transmission rate in the photonie crystal and air tank boundaries, so resonance could happen at a certain wavelength. The results indicate that the refractive index can be measured with high sensitivity using this open photonie crystal cavity whose resonance wavelength varies with the refractive index.