Transmission Enhancement Of Hollow Pyramid Metal Waveguides Embedded With Dielectric Microspheres

Obtaining high transmittance micro-nano optical fields is an important research direction in nanophotonics,which plays an important role in promoting the wide application of integrated optics.Related technologies have broad application prospects in the fields of super-resolution optical imaging,optical data storage,nano-optical circuits,nano-manipulation,nano-lithography,fluorescence sensitivity,application of solar cell,etc.With the development of nanotechnology,the techniques for obtaining highintensity transmission light field are emerging in endlessly.Among them,hollow pyramidal metal waveguides(HPMWs)are one of the most important techniques to obtain small-scale high-intensity light field and to realize effective transmission and coupling.Due to the shielding effect of the metal wall against external interference,the signal light field is completely isolated from the external environment,so the smallscale light field obtained by HPMWs has the advantages of low background noise,the light field size easy to control and isolation from external interference.However,restricted by the physical mechanism of sharp attenuation of evanescent field,the light field intensity of the outlet port will decrease sharply with the decrease of the aperture of the outlet,which becomes the main obstacle to the wider application of HPMWs in micro-nano optical devices.In this dissertation,we propose a novel method to enhance the transmittance of nanoscale transmission field of HPMWs through exciting surface plasmon by embedding dielectric microspheres.The finite-difference time domain method is used for numerical research.It is found that,different from the conventional hollow pyramidal metal waveguide without microsphere,the output light field is mainly derived from the resonance excitation,efficient amplification and transmission of the surface plasmons and the gap surface plasmons.By comparing the transmittance of the HPMW with and without microspheres under the same external parameter environment,it is found that the transmittance of the HPMW with dielectric microspheres is greatly enhanced,and its maximum enhancement is 41.3 times that without dielectric microsphere.