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Articles 1 - 4 of 4
Full-Text Articles in Electrical and Computer Engineering
Infrared Quarter-Wave Reflection Retarders Designed With High-Spatial-Frequency Dielectric Surface-Relief Gratings On A Gold Substrate At Oblique Incidence, Jian Liu, Rasheed M.A. Azzam
Infrared Quarter-Wave Reflection Retarders Designed With High-Spatial-Frequency Dielectric Surface-Relief Gratings On A Gold Substrate At Oblique Incidence, Jian Liu, Rasheed M.A. Azzam
Electrical Engineering Faculty Publications
One- and two-dimensional high-spatial-frequency dielectric surface-relief gratings on a Au substrate are used to design a high-reflectance quarter-wave retarder at 70° angle of incidence and 10.6-μm light wavelength. The equivalent homogeneous anisotropic layer model is used. It is shown that equal and high reflectances (>98.5%) for the p and the spolarizations and quarter-wave retardation can be achieved with two-dimensional ZnS surface-relief gratings. Sensitivities to changes of incidence angle, light wavelength, grating filling factor, and grating layer thickness are considered.
Determination Of The Refractive Index And Thickness Of Transparent Pellicles By Use Of The Polarization-Independent Absentee-Layer Condition, Y. Cui, R. M.A. Azzam
Determination Of The Refractive Index And Thickness Of Transparent Pellicles By Use Of The Polarization-Independent Absentee-Layer Condition, Y. Cui, R. M.A. Azzam
Electrical Engineering Faculty Publications
The refractive index and the thickness of a transparent pellicle are determined when the pellicle is placed between two vertical crossed polarizers and rotated in the horizontal plane. The transmission axes of the polarizers are neither parallel nor perpendicular to the plane of incidence. The light transmitted through the crossed polarizers reaches a minimum when the pellicle satisfies the absentee-layer condition. The refractive index and the film thickness are obtained from the pellicle orientation angles under such a condition.
Applications Of The Normal-Incidence Rotating-Sample Ellipsometer To High- And Low-Spatial-Frequency Gratings, Y. Cui, R. M.A. Azzam
Applications Of The Normal-Incidence Rotating-Sample Ellipsometer To High- And Low-Spatial-Frequency Gratings, Y. Cui, R. M.A. Azzam
Electrical Engineering Faculty Publications
The normal-incidence rotating-sample ellipsometer is an instrument that can be used to characterize grating surfaces from the measured ratio ρof complex reflection coefficients ry/rx of light polarized perpendicular and parallel to the grating groove direction. Experimental results at different wavelengths for different gratings with spatial frequencies from 150 to 5880 grooves/mm are presented. The groove depth of the 5880-grooves/mm gold-coated grating can be estimated from the measured ρ and rigorous grating theory.
Extended Kalman Filter For Photographic Data From Impact Acceleration Tests, Edit J. Kaminsky, R. E. Trahan, P. M. Chirlian, B. King
Extended Kalman Filter For Photographic Data From Impact Acceleration Tests, Edit J. Kaminsky, R. E. Trahan, P. M. Chirlian, B. King
Electrical Engineering Faculty Publications
This paper presents the development of an Extended Kalman Filter (EKF) that optimally processes photographic data collected during short-duration impact acceleration tests. The system is modeled by a non-linear state-space representation using quaternions for rotational kinematics. Three cameras are used to photograph up to 14 fiducials mounted on a plate attached to the subject's mouth. The filter yields the history of the rotational and translational kinematics of the origin of the mouth plate. Results from the EKF and analysis of the estimation error are presented.