为了掌握光子晶体空气孔中液体质量分数对禁带宽度的影响,利用平面波展开法研究了由椭圆形空气孔介质周期性排列的长方晶格光子晶体在不同偏振模式下的禁带宽度。数值模拟显示:溶液的质量分数变化与光子晶体带隙宽度或输出功率变化接近线性关系,而线性相关程度受填充空气孔内液体质量分数的影响。进行了多组参数比对与优化,最终获得了线性度最高的禁带宽度和输出功率与溶液质量分数的对应关系。基于这个对应关系,提出了基于光子晶体带隙宽度测量的溶液质量分数检测方法。该方法可被应用于各蛋白质聚集探测、快速检测气体或液体质量分数、DNA检测等领域。

In order to grasp the effect of solution mass fraction in the air hole of the photonic crystal on the band gap, the band gap width of rectangular lattice photonic crystal with periodic array of air holes in different polarization modes is studied by using plane wave expansion method. A two-dimensional rectangular lattice photonic crystal material Si is chosen as the substrate, filling the air hole with different solution of copper nitrate mass fraction materials which will be measured, and the photonic band gap width of the photonic crystal filled with solution mass fraction under different polarization modes is obtained. Simulation results show that the concentration change of solution mass fraction has a linear relationship with band gap width or output power changes and the linear correlation degree is affected by background medium column material. The obtained multiple parameters are compared and optimized, and eventually the linearity relationship between the band gap width or highest output power and the concentration of solution mass fraction is obtained. Based on this relation, a solution concentration detection method based on photonic crystal band gap width is proposed. This test method can be used in various protein aggregation detection, rapid detection of gas and the concentration of solution mass fraction, DNA testing, etc.