Design For Plasmonic High Q Resonance Microstructures And Investigation Of Their Spectral Poperties

In nano-photonics and optoelectronics,high Q resonance microstructure devices have a very wide range of applications,such as spectral selective thermal emission,sensing,single photon emission,filtering,optical tweezers,quantum optics,and other fields.Based on the finite-difference time-domain method,two high Q resonance microstructures are designed and studied in this paper.The main contents are as follows:A perfect MIM plasma absorber with a double asymmetric H-shaped nanocolumn array is proposed.Compared with the symmetric H-shaped nanocolumn array,three sharp absorption peaks are obtained.The three sharp absorption peaks achieve perfect absorption in the near infrared range with a minimum half-peak full width of 3.1 nm,a maximum Q factor of 260,and an absorption amplitude of more than 99.2%.In addition,it has been proven that the absorber has high-performance sensing characteristics.Sensitivity and quality factors are studied by changing the spectral response of the ambient refractive index.The results show that the sensitivity of the three resonant absorption peaks is 788.0 nm/RIU,674.5 nm/RIU,and 697.9 nm/RIU,respectively,and the corresponding quality factors are 254.2,92.4,and 110.8,respectively.A symmetric dimer-trapezoidal silicon nanorod metasurface is proposed for a near-infrared refractive index sensor.The metasurface structure produces two Fano resonance transmission peaks with a high quality factors at near infrared wavelengths.By studying and analyzing the physical mechanism of the two Fano resonances,the principle of Fano resonance generation is confirmed.After that,the influence of the geometric parameters of the structure on the Fano resonance transmission peaks is analyzed,and it is found that the two Fano resonance transmission peaks can be controlled simultaneously or independently.In addition,by changing the polarization angle of the incident light,fano resonance can be turned on and off,and its modulation depth can be controlled.Finally,by changing the ambient refractive index around the structure,the sensing performance of the hypersurface was analyzed,and the sensitivity of the two Fano resonance transmission peaks was obtained as 807.8 nm/RIU and 933.3nm/RIU,respectively.The corresponding maximum FOM values were 471 and 1681,and the maximum Q factor were 1063 and 3369,respectively.