晶格旋转光子晶体Mach-Zehnder干涉结构传感特性

基于光子晶体的自准直效应,利用在同一背景折射率下不同介质柱的等效折射率的不同,提出了一种基于晶格旋转的二维光子晶体Mach-Zehnder干涉仪折射率传感器。分别应用线缺陷和空气平板波导构成其分束镜和全反镜,并在其中一个干涉臂上设置传感区域。通过改变填充到传感区域溶液的浓度,改变介质柱的折射率,进而影响透射谱的中心波长,从而建立起溶液浓度和透射波长之间的数学关系;并进行了酒精溶液浓度测量的数值模拟,结果表明,该传感器在1.33~1.37折射率变化范围内灵敏度为250nm/RIU。

Sensing property analysis on lattice rotating photonic crystal Mach-Zehnder interferometer

We propose a compact photonic crystal Mach-Zehnder interferometer index sensor with a two-dimensional rotated square lattice, based on the photonic crystal self-collimation effect. Using the same background index, the different index of the circular rods has different effective index. The line defected and the air slab waveguide are respectively used as the beam splitter and mirror of the interferometer, and a sensing area is setting on one arm of the interferometer. The index of the circular rods changes with the concentration of the solution filled into the sensing region, thereby affecting the center wavelength of the transmission spectrum, and establishing a mathematical relationship between the solution concentration and the transmission wavelength. Then we carry out a numerical simulation of the concentration measurement of the alcohol solution, the results show that the sensor sensitivity is 250 nm/RIU in the refractive index variation within the scope of 1.33-1.37.