基于全介质微腔双通道超材料的光学吸收器研究  

Research on Optical Absorber Based on All Dielectric Microcavity Dual-Channel Metamaterial

作　　者：黄慧萍[1] HUANG Hui-ping(Xiamen Huatian Foreign Vocational and Technical College,Xiamen 361000,China)

机构地区：[1]厦门华天涉外职业技术学院,福建厦门361000

出　　处：《光学与光电技术》2024年第5期143-152,共10页Optics & Optoelectronic Technology

摘　　要：基于全介质超材料吸收器相关理论基础,设计了一种可用于折射率传感应用的微腔结构吸收器.通过数值模拟得出,该吸收器在波长539 nm和673 nm处分别实现了99.91%和99.96%的吸收,与自由空间阻抗匹配完美,半高全宽分别为11 nm和5 nm.通过共振波长处的电磁场分布情况解释了吸收机理主要基于Mie谐振,并分析了吸收器对偏振角度不敏感的特性.通过改变吸收器的结构参数,研究了吸收峰值和吸收频段的变化情况,并对其结构的传感性能进行分析.双通道吸收器作为折射率传感器的FWHM、灵敏度S、FOM和FOM*是根据两个吸收峰作为环纳米腔宽度的函数计算的.改变周围介质折射率由1.00变化至1.08时,灵敏度S值可达到175 nm/RIU和212 nm/RIU.当圆环形纳米腔宽度从20 nm增加到100 nm时,峰值1的灵敏度S值由146 nm/RIU增加至201 nm/RIU,而峰2的灵敏度S值稳保持在200 nm/RIU左右.峰1的FOM值从8.2缓慢增加到23.6,而峰2的FOM由于其频带较窄,FOM最大值可达65.3.此外,还计算了双波段吸收器在539 nm和673 nm共振波长处的FOM*分别为17265和59902.该吸收器可以在可见波段内实现双通道高吸收,作为折射率传感器使用时,具有高灵敏度和窄带的优点.这种微腔结构的吸收器在未来环境监测和光电探测方面具有潜在的应用价值.Based on the theory of all-dielectric metamaterial absorber,a new type of micro-cavity structure absorber for refractive index sensor is designed.Numerical simulations show that the absorber achieves 99.91%and 99.96%absorption at 539 nm and 673 nm,respectively,and is well matched with the Impedance of free space.The full width at half height is 11 nm and at half width is 5 nm,respectively.The absorption mechanism based on Mie resonance is explained by the electromagnetic field distribution at resonance wavelength,and the characteristics of the absorber which is insensitive to polarization angle are analyzed.The changes of absorption peak value and absorption frequency band are studied by changing the structure parameters of the absorber,and the sensing performance of the structure is analyzed.The FWHM,sensitivity S,FOM and FOM*of the two-channel absorber as the refractive index sensor are calculated based on the two absorption peaks as a function of the width of the ring nano-cavity.When the refractive index of the surrounding medium is changed from 1.00 to 1.08,the sensitivity s value can reach 175 nm/RIU and 212 nm/RIU.The sensitivity s value of peak 1 increased from 146 nm/RIU to 201 nm/RIU,while the sensitivity S value of Peak 2 remained stable at about 200 nm/RIU when the width of the annular nano-cavity increased from 20 nm to 100 nm.The FOM value of peak 1 increased slowly from 8.2 to 23.6,while that of Peak 2 was 65.3 because of its narrow frequency band.In addition,the FOM*values of the dual-band absorber at 539 nm and 673 nm resonant wavelengths are calculated to be 17265 and 59902,respectively.The absorber can achieve double-channel high absorption in the visible band,and has the advantages of high sensitivity and narrow band when used as a refractive index sensor.The microcavity structure of the absorber has potential applications in future Environmental monitoring and photoelectric detection.

关 键 词：超材料吸收器 全介质 微腔 可见光 折射率传感器 

分 类 号：O441.4[理学—电磁学]