Characters Of Optical Surface Electromagnetic Waves And Fabrication Of A Dielectric Superlattice Adjacent To Nano Structures

We theoretically and experimentally reveal that the large resonant optical transmission (ROT) can be realized through a dielectric supper lattice adjacent to a thin metal film, at a frequency in the original band-gap of the photonic crystal (PC). The influence of periodic number of PC and the thickness of the adjacent metal on the transmission frequency and intensity is studied in detail. An optimum design is given to reach the maximum transmission efficiency, meanwhile a mechanism underlining the ROT phenomenon is proposed. An effective admittance-matching theory is proposed to understand this effect and quantitatively determine the operating frequency, which matches very well with the simulated and measured results. The effects might be very useful to realize some optical filters and sensor devices since the structure is easy for mass production and is matured technically to be prepared in industry.We also studied the surface electromagnetic waves (SEWs) in a dielectric supper lattice, which can be excited when the wave vector of incident light matches the momentum of SEWs. We managed to fabricate Ag grating on top of a dielectric supper lattice by Nano-imprint lithography, inductively coupled plasma etching, electron beam evaporation deposition and lift off technology. We have optimized the etching recipe to etch the residual layer of the UV-Resist. This Ag grating excite the SEWs of the dielectric supper lattice by coupling the reciprocal lattice vector of Ag grating and SEWs wave vector. Furthermore, more than one surface mode can be excited without changing the parameter of the grating-supper lattice structure because of the multi-order characteristics of the grating reciprocal lattice vector. This design offers promising potential in many applications about SEWs.