The Femtosecond Laser Field Enhancement Of Several Typical Nanostructures

The near field enhancement can be achieved with plasmonon the interface of metal and dielectric. The plasmon nanostructure of beyond diffrection-limited is widely used in light signal transmission. The enhancement with the Local surface plasmon resonance depend on the size and the scale of nanostructue.In this thesis, we show some troditional nanostructure:sphere,cylindrt,moon,#, nanosta rand analyse the effects of parameters of namostructure to near field enhancement.The extinction cross section(ECS) of nanosphere will be red-shift with the radius increa sed. The ECS of cyline will be red-shift with length increased.We can find a multripole mod e excited with the short wave illuminating. For#structure, an increasi-ng of the arm will cau se the ECS red-shift and the near field enhancement will be higher. Ahigher field enhancee ment can be generated with a smaller gap between two moons.We can achieve the controlab le exciting in nanostar with changing the polarization and wavelength of the source.