Optical Anomalous Transmission And Special Curved Beam Regulation Studies

Surface plasmon (SP), which is a kind of electromagnetic mode caused by the interaction between the free charges on the metal surface and the incident electromagnetic wave, have gained increasing attention due to their unusual optical properties. Surface plasmon is very sensitive to the shape and size of the nanostructure, the environmental material and the alignment of the nanostructures. So, we can adjust the factors mentioned above to manipulate the surface plasmon of the nanostructure for applying in many research fields.Since the extraordinary optical transmission(EOT) of the periodic array of subwavelength nanohole in the thin metal films was found, the physical mechanism and application of the surface plasmon polaritons (SPPs) have maken breakthroughs. With the development of theory and advances in micro fabrication technology, the research of metal nanostructure system becomes a new quickly developing subject, namely surface plasmonics, which has present more than potentials on some fields, such as surface enhanced Raman spectroscopy, solar cells. In addition, with the research of international researchers on integrated optical circuit, researchers proposed a specific, complex plasma integrated circuit, which gradually has become a developing trend. However, in order to the meet the requirements mentioned above, the free-space beams and beam path diversity is more higher. In this paper, the optical transmission of the metal micro-nano structure and special bending beam control are studied, the specific contents and results as follows:(1) We designed the structure of multilayer metal slit arrays, and apply the finite element method to investigate the extraordinary optical transmission of the arrays structure. Results show that, compared with monolayer metallic slit arrays structure, multilayer metallic slit arrays can achieve enhancing electric fields in the dielectric layer and there are more transmission peaks in the spectra. In addition, the effects of the position of the dielectric layer and the period of the arrays on the transmission property are also studied. Results show that, with the change of the dielectric position or other structural parameters, the transmission spectra appears red shift or blue shift. These results would be helpful for tuning transmission peak and understanding the mechanism of EOT phenomena of multilayer metallic slits.(2) We designed the array of non-periodic grooves, and apply the finite element method to investigate the arbitrary bending plasmonic beam. In addition, in this paper, the corresponding electric field distribution of the structural parameters, the constant and the incident wavelength are also calculated. Results show that, For the same target curve, along with the constant a increases, the beam bending degree increase, propagation distance is reduced, and the theory is applicable to many wavelengths, the width of the groove has small effect on the morphology of spatial arbitrary curved beam basically, and found that both structural parameter and constant change, its corresponding beam have self-transverse bending and non-diffracting characteristics, these results in the optical fiber sensing have important potential applications, such as optical trapping, manipulation and optical integration.