The radiative properties of a gold surface with one-dimensional Gaussian random roughness distribution were obtained with the finite-difference time-domain （FDTD） method and the recursive convolution treatment of th...The radiative properties of a gold surface with one-dimensional Gaussian random roughness distribution were obtained with the finite-difference time-domain （FDTD） method and the recursive convolution treatment of the Drude Model. The bi-directional reflection distribution function （BRDF） for both TM mode and TE mode were obtained and compared with the highly accurate experimental data from the earlier work. The incident wavelength varies from 1.152 μm to 3.392 μm and incident angle is at 300-70°, respectively. The results show that, the predicted values and experimental results are in good agreement. The highly specular peak in the BRDF is reproduced in the numerical simulations, and the increase of the TM mode BRDF is found to be attributed to the effect of a variation in the optical constant at the incident wavelength period.展开更多
Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or...Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or both slit sides. Although the side length of features is one or two orders of magnitude shorter than the wavelength, the attached nanoscale features can modify the transmittance significantly. The transmittance was also further investigated in detail by looking into the electromagnetic fields and Poynting vectors of selected slit geometries. The investigation results show that such change can be attributed to the cavity resonance effect inside the slit arrays. The work is of great importance to the wavelength-selective devices design in optical devices and thermal application fields.展开更多
基金Project(N110204015) supported by the Fundamental Research Funds for the Central Universities
文摘The radiative properties of a gold surface with one-dimensional Gaussian random roughness distribution were obtained with the finite-difference time-domain （FDTD） method and the recursive convolution treatment of the Drude Model. The bi-directional reflection distribution function （BRDF） for both TM mode and TE mode were obtained and compared with the highly accurate experimental data from the earlier work. The incident wavelength varies from 1.152 μm to 3.392 μm and incident angle is at 300-70°, respectively. The results show that, the predicted values and experimental results are in good agreement. The highly specular peak in the BRDF is reproduced in the numerical simulations, and the increase of the TM mode BRDF is found to be attributed to the effect of a variation in the optical constant at the incident wavelength period.
基金Project(N110402015) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(2012M510075) supported by China Postdoctoral Science Foundation
文摘Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or both slit sides. Although the side length of features is one or two orders of magnitude shorter than the wavelength, the attached nanoscale features can modify the transmittance significantly. The transmittance was also further investigated in detail by looking into the electromagnetic fields and Poynting vectors of selected slit geometries. The investigation results show that such change can be attributed to the cavity resonance effect inside the slit arrays. The work is of great importance to the wavelength-selective devices design in optical devices and thermal application fields.
