Design And Research Of High Q Metal Micro/Nano Devices Based On Surface Plasmon

High Q metal micro/nano devices have broad application prospects in nanophonics and optoelectronics.They have high application value in spectral selective emission,absorption filting,nano-laser,quantum optics,optical tweezers and so on.However,due to the inherent ohmic loss and radiation damping in metal micro/nano structures,it is difficult to obtain ultra-narrow surface plasmon resonance and design metal micro/nano devices with high Q value.In this paper,three kinds of high-Q metal micro/nano devices based on surface plasmon are designed and studied by the FDTD method.The following are the main contents:1、A high-Q metal micro/nano filter based on stacked low index and high index dielectric(LID–HID)substrate is proposed.Transmission peaks with high quality factor and multiple high quality factor resonances were obtained by ultra-narrow metal nano slit arrays based on LID-HID substrate.By stacking LID-HID dielectric layer,the number transmission peaks and quality factor can be modulated freely.By optimizing the structural parameters of the three-layer lid-hid dielectric layer,the linewidth of the transmission peak can be reduced to the limit of 1nm,and the quality factor(Q)can reach 700.This study provides a theoretical basis for the design of multi-band nano photonic devices with high quality factor and has potential application prospects in the next generation of high-resolution plasma biosensor and filtering technology.2、A high-Q dual channel metal nano perfect absorber is proposed.A dielectric layer is deposited on a gold substrate and a crossed double nanorods array is prepared on it.Based on the higher-order resonance and Bloch like resonance in crossed nanorods,the proposed planar metamaterial structure can realize multiple high absorption narrow-band resonance peaks.There are two almost perfect absorption peaks at 905 nm and 1161 nm,whose FWHM are18 nm and 19 nm,respectively.All peaks have an absorption rate of more than 90%.The structure has great application potential in solar photovoltaic industry,biosensors,optical switches and filters.3、An asymmetric square ring resonator based on MIM waveguide is proposed.The first-order resonant mode and the second-order resonant mode can be modulated by adjusting the longitudinal distance(Δz)and transverse distance(Δx).With the change ofΔz orΔx,the two second-order resonant modes in the asymmetric square ring resonator can be coupled with each other and enhance the absorption,and the first-order resonant mode splits at the same time.This research provides a new idea to improve the Q value of resonance,whose results have great application potential in sensing and filtering.