Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation. The influence of flux angle on the surface morphology and microstructure is investigated by scanning electron microscopy （SEM）. ...Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation. The influence of flux angle on the surface morphology and microstructure is investigated by scanning electron microscopy （SEM）. The Ta2O5 thin films are anisotropic with highly orientated nanostructure of slanted columns. The porous microstructure of the as-deposited films results in the decrease of effective refractive index and packing density with increasing deposition angle. The anisotropic structure results in optical birefringence. The in-plane birefringence increases with the increase of deposition angle and reaches the maximum of 0.055 at the deposition angle of 70°. Anisotropic microstructure and critical packing density are the two key factors to influence the in-plane birefringence.展开更多
A guided-mode resonance（GMR） filter with the same material（Ta_2O_5） for both the grating layer and the waveguide layer is designed and fabricated.This simple structure is easy to fabricate and can avoid the defect...A guided-mode resonance（GMR） filter with the same material（Ta_2O_5） for both the grating layer and the waveguide layer is designed and fabricated.This simple structure is easy to fabricate and can avoid the defects at the grating/waveguide interface using different materials.The spectral response measured with a Lambda 900 spectrophotometer under normal incidence for TE waves exhibits a peak reflectance exceeding 80%at the wavelength of 1040 nm with a full-width half-maximum（FWHM） linewidth of 23 nm.We evaluate the deviations of the fabricated structure from the designed parameters.展开更多
基金supported by the National Natural Science Foundation of China (No.60778026)the Shanghai Rising-Star Program (No.07QB14006)
文摘Tantalum pentoxide thin films are prepared by oblique angle electron beam evaporation. The influence of flux angle on the surface morphology and microstructure is investigated by scanning electron microscopy （SEM）. The Ta2O5 thin films are anisotropic with highly orientated nanostructure of slanted columns. The porous microstructure of the as-deposited films results in the decrease of effective refractive index and packing density with increasing deposition angle. The anisotropic structure results in optical birefringence. The in-plane birefringence increases with the increase of deposition angle and reaches the maximum of 0.055 at the deposition angle of 70°. Anisotropic microstructure and critical packing density are the two key factors to influence the in-plane birefringence.
基金supported by the National Natural Science Foundation of China under Grant No.10704079.
文摘A guided-mode resonance（GMR） filter with the same material（Ta_2O_5） for both the grating layer and the waveguide layer is designed and fabricated.This simple structure is easy to fabricate and can avoid the defects at the grating/waveguide interface using different materials.The spectral response measured with a Lambda 900 spectrophotometer under normal incidence for TE waves exhibits a peak reflectance exceeding 80%at the wavelength of 1040 nm with a full-width half-maximum（FWHM） linewidth of 23 nm.We evaluate the deviations of the fabricated structure from the designed parameters.
