Naslov
A Nonparaxial Scalar Treatment of Diffraction Grating Behavior

Autori
Bogunović, Dijana

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, magistarski rad

Fakultet
School of Optics

Mjesto
Orlando, Florida, USA

Datum
28.06

Godina
2002

Stranica
138

Mentor
Harvey, J. E.

Ključne riječi
diffraction; aberrations

Sažetak
Scalar diffraction theory is frequently considered inadequate for predicting diffraction efficiencies for grating applications where l/d > 0.1. It has also been stated that scalar theory imposes energy upon the evanescent diffracted orders. These notions, as well as several other common misconceptions, are driven more by an unnecessary paraxial approximation than the scalar limitation. By scaling the spatial variables by the wavelength, the Rayleigh-Sommerfeld diffraction integral can be written in the form of a Fourier transform integral of a generalized pupil function that contains phase variations, which are identified with wavefront aberrations. Third order aberrations will be investigated in detail (defocus, coma, astigmatism and distortion). It will be shown that diffracted radiance is shift-invariant in direction cosine space. Thus simple Fourier techniques can be used to predict a variety of wide-angle (non-paraxial) diffraction grating effects. These include: the redistribution of energy from the evanescent orders to the propagating ones and diffraction efficiencies predicted with an accuracy usually thought to require rigorous electromagnetic theory. Diffraction efficiencies of perfectly conducting sinusoidal, lamellar and blazed gratings will be calculated in non-paraxial region and compared with rigorous electro-magnetic theory.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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