Properties Of Surface Plasmon Polaritons Of Zinc Oxide

Surface plasmon resonance,as an emerging research area has attracted a great deal of interest in the past decades.The exitation of surface plasmon polaritons(SPPs)enables the manipulation of light on the subwavelength scale,which paves a way for developing integrated optical tenologies.The advances of research on surface plasmon polaritons depends on the plasmonic materia,conventional noble metals lose the property of field comfinement in the long wavelength infrared region.In this thesis,we investigate the surface plasmon polaritons in a new material of multilayered Zn O films.The main work and achivements of this thesis are summarized as below.(1)Theoreticl model for surface plasmon polaritons in Zn O is introduced firstly.The wave equations of metal/dielectric structures are solved by using Maxwell's equations.Their dispersion relations and propagation modes of surface plasmons are obtained and solved.(2)Al-doped multilayered Zn O films are fabricated by using the atomic layer deposition(ALD).Sample with different recycle ratios were made.All samples were prepared on a 1 mm thick quartz substrate.The sample 1: consists of Zn O only and does not contain Al Ox layers.The other four samples have different Zn O cycle ratios,namely1:14,1:19,1:24,and 1:49,respectively.(3)The unique properties of surface plasmon polaritons in the multilayered Zn O films are revealed using infrared reflection spectroscopy.By measuring the infrared reflection spectrum of the sample when the incident light is at a 15 degree angle,the Drude model parameters of the multilayered Zn O films with different doping ratios are extracted by using a two-layer transmission matrix model.The dispersion of surface plasmon polaritons of Zn O films are then obtained,and their propagation properties are analyzed and compared with noble metals.The results show that the surface plasmon based on doped zinc oxide has the subwavelength propagation characteristics in the long wavelength infrared.Its field energy can be confined to the sub-wavelength scale.With the effective skin depth is one order of magnitude smaller than that of noble metals.Meanwhile,its propagation length is on the order of 100 micrometers and are three orders of magnitude smaller than that of noble metals.Therefore,the studied Zn O films exhibit a superior property of optical comfinement,as well as a higher loss.