Browsing by Subject "Optical wave propagation"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Local error analysis arising from the conventional scalar approximation in wide optical fields(IEEE, 2017) Külçe, Onur; Onural, LeventThe 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.Item Open Access Signal processing issues in diffraction and holographic 3DTV(IEEE, 2005) Onural, Levent; Özaktaş, Haldun M.Image capture and image display will most likely be decoupled in future 3DTV systems. For this reason, as well as the need to convert abstract representations to display driver signals, and the need to explicitly consider diffraction and propagation effects, it is expected that signal processing issues will play a fundamental role in achieving 3DTV operation. Since diffraction between two parallel planes is equivalent to a 2D linear shift-invariant system, various signal processing techniques play an important role. Diffraction between tilted planes can also be modeled as a relatively simple system, leading to efficient discrete computations. Two fundamental problems are digital computation of the optical field due to a 3D object, and finding the driver signals for a given optical device so as to generate the desired optical field in space. The discretization of optical signals leads to several interesting issues; for example, it is possible to violate the Nyquist rate while sampling, but still maintain full reconstruction. The fractional Fourier transform is another signal processing tool which finds application in optical wave propagation.