Evaluation of the validity of the scalar approximation in optical wave propagation using a systems approach and an accurate digital electromagnetic model
Date
2016Source Title
Journal of Modern Optics
Print ISSN
0950-0340
Publisher
Taylor and Francis Ltd.
Volume
63
Issue
21
Pages
2382 - 2391
Language
English
Type
ArticleItem Usage Stats
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Abstract
The cause and amount of error arising from the use of the scalar approximation in monochromatic optical wave propagation are discussed using a signals and systems formulation. Based on Gauss’s Law, the longitudinal component of an electric field is computed from the transverse components by passing the latter through a two input single output linear shift-invariant system. The system is analytically characterized both in the space and frequency domains. For propagating waves, the large response for the frequencies near the limiting wave number indicates the small angle requirement for the validity of the scalar approximation. Also, a discrete simulator is developed to compute the longitudinal component from the transverse components for monochromatic propagating electric fields. The simulator output helps to evaluate the validity of the scalar approximation when the system output cannot be analytically calculated. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Keywords
Computation of the longitudinal componentDigital simulator
Electromagnetic wave propagation
Error in the scalar optics approximation
Fourier optics
Signals and systems model