Browsing by Subject "Longitudinal components"

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Open Access
Analysis of the longitudinal component of the electric field generated by flat and pixelated liquid crystal displays
(IEEE, 2016-07) Külçe, Onur; Onural, Levent
The longitudinal, z, component of the electric field is investigated for the pixelated and flat liquid crystal displays (LCDs) for monochromatic case. The pixelation process is assumed to occur in free space. The z component is computed in the Fourier domain by using Gauss's Law from the x and y components of the output electric field. The effect of the display parameters are discussed for a y polarized display in a phase only operation. It is found that, in the low frequency regions, the size of the region of the large magnitudes becomes smaller as the width of the active region increases. Moreover, the validity of the scalar theory for a single pixel is evaluated for varying pixel sizes. It is shown that, when the ratio of the width of the active region to wavelength is between 1.5 and 5, the error decays with oscillations between 43% and 5%. When that ratio is larger than 15, the error does not exceed 3%. © 2016 IEEE.
Open Access
Local error analysis arising from the conventional scalar approximation in wide optical fields
(IEEE, 2017) Külçe, Onur; Onural, Levent
The scalar approximation which is used to represent the optical fields in free space causes large error in large angles due to the neglected longitudinal component of the vector electric field. A short space Fourier transform (STFT) based space-frequency analysis method is proposed to analyze the local error in wide extent optical fields. The error measure is quantitatively defined as the ratio of the local power of the longitudinal component to the local power of the total electric field. The error is analyzed on both parallel and tilted planes with respect to the display that produces the optical field. Moreover, a simulation result for a scalar wave that includes different frequency components at different locations shows that the local error becomes high at the locations where high frequency components exist. The proposed method can be used to analyze the local error, if the the scalar approximation is to be used for the optical field to be generated.