| Alkali metal tantalate niobate materials have significant application in opto-electronic process due to its excellent electro-optic effect.And the electro-optic modulation voltage will decrease dramatically because of smaller thickness of thin film comparing with bulk material,which will promote the development of nanosecond or subnanosecond photoswitch.Therefore,in order to investigate the problems specific to the process of tantalate niobate films with largest electro-optic coefficient so far,preparing pure KLTN opto-electronic thin film,and investigating optical properties and transmission properties have practical significance for the application of opto-electronic modulation.The tantalate niobate based KTa0.5Nb0.5O3?KTN50??KTa0.65Nb0.35O3?KTN65?and K0.95Li0.05Ta0.65Nb0.35O3?KLTN65?films with perovskite structure were successfully prepared using pulsed laser deposition?PLD?technique.The optimal growth situation of films using PLD were determined through the investigation of growth properties in theory and experiment.The results of charactered structure and microtopography indicate that the degree of orientation of?h00?is 94.6%,and the size of crystalline grains are 50-100 nm.The transmission properties of plasma plume in the process of preparing KTN film using PLD technique were investigated specific to the impurity phase caused by stoichiometric deviation of particles,and the concentration distribution of plasma plume were obtained.Moreover,the deposition rules of K,Nb and Ta atoms were determined in the basis of theoretical analysis,which has provided assistances for controlled growth of tantalate niobate based films.The transmission,absorption spectrum,and refractive optical properties of KTN films were investigated by ultraviolet-visible spectrophotometer,ellipsometer and Z-scan,respectively.The thickness of the films were determined according tospectrum properties,and the broadened energy gap of KTN films were analyzed as well.The refractive equation parameters of KTN films grown on Pt?111?/Ti/SiO2/Si substrate were calculated based on refractive dispersion properties.The nonlinear refractive coefficient are-6.59 × 10-10cm2/W by means of third order nonlinear optical properties,indicating that the KTN films in the circumstance of laser with532 nm wavelength ? 8ns pulse width and 0.48GW/cm2 power density possess self-defocusing properties.In order to explore the potential application in optical device of KTN films,the slab waveguide based KTN/Mg O and ITO/KTN/Pt film were simulated.The optical mode in KTN film waveguide were obtained from frequency analysis and boundry mode analysis,and the transmission efficiency of TE mode in different geometry size of the film waveguide were investigated.The light field with higher transmission efficiency and lower transmission loss can transmit normally in KTN film with 200-500 nm thickness under 632.8nm work wavelength. |
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