Topic
Diffraction efficiency
About: Diffraction efficiency is a research topic. Over the lifetime, 10320 publications have been published within this topic receiving 158298 citations.
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TL;DR: Bragg gratings with sidelobe levels 26 dB lower than the peak reflectivity have been fabricated in standard telecommunication optical fibres by exposure to ultraviolet light through a phase mask with a locally varying diffraction efficiency as mentioned in this paper.
Abstract: Bragg gratings with sidelobe levels 26 dB lower than the peak reflectivity have been fabricated in standard telecommunication optical fibres by exposure to ultraviolet light through a phase mask with a locally varying diffraction efficiency This represents a reduction of 14 dB in the sidelobe levels compared to uniform gratings with the same bandwidth and reflectivity
135 citations
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TL;DR: In this paper, the authors extended Burckhardt's solution for diffraction from a thick grating to include complex dielectric constants and nonsinusoidal stratifications, which allowed any realistic periodic structure to be handled.
Abstract: This paper extends Burckhardt’s solution for diffraction from a thick grating to include complex dielectric constants and nonsinusoidal stratifications. This allows any realistic periodic structure to be handled. Computed results are compared with coupled-wave theory, as described by Kogelnik, with emphasis on strongly absorbing gratings such as those made by photographing an interference pattern. Finally, some experimental holographic data are compared with computations that take into account the photographic nonlinearity between exposure and dielectric constant.
135 citations
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TL;DR: In this paper, a poly(4-nitrophenyl)-3-[N-[2-(methacryloyloxy)ethyl]carbazolyl]]diazene was prepared and its photoinduced birefringence, diffraction grating, and photorefractive asymmetric two-beam gain coupling were studied.
Abstract: Poly{(4-nitrophenyl)-3-[N-[2-(methacryloyloxy)ethyl]carbazolyl]]diazene} was prepared and its photoinduced birefringence, diffraction grating, and photorefractive asymmetric two-beam gain coupling were studied. The monomer was obtained by performing azo coupling in a two-phase water−dichloromethane system in the presence of a phase transfer catalyst. Photoinduced birefringence of up to 0.09 was observed and diffraction efficiencies of up to 25% were obtained, with atomic force microscopy studies revealing that the grating profile exhibited a sinusoidal shape. Asymmetric two-beam coupling is observed, indicating photorefractive properties, but the energy transfer phenomena are more complex, involving also diffraction by the photoinduced gratings. The combination of these three optical propertiesphotoinduced birefringence, surface gratings, and two-beam couplingis believed to be unique and may eventually produce an all-optical device built of a single polymer film.
134 citations
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TL;DR: Special phase gratings are described by means of which the red, green, and blue color components of colored objects are generated side by side around the optical axis in the image plane of a lens.
Abstract: Special phase gratings are described by means of which the red, green, and blue color components of colored objects are generated side by side around the optical axis in the image plane of a lens. An analysis of these color separation gratings is given, and theoretical and experimental results for some grating samples are presented.
133 citations
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TL;DR: The integrated efficiency is shown to be the limiting value for the optical transfer function; in most cases it serves as an overall scale factor for the transfer function.
Abstract: Diffractive lenses differ from conventional optical elements in that they can produce more than one image because of the presence of more than one diffraction order. These spurious, defocused images serve to lower the contrast of the desired image. We show that a quantity that we define as the integrated efficiency serves as a useful figure of merit to describe diffractive lenses. The integrated efficiency is shown to be the limiting value for the optical transfer function; in most cases it serves as an overall scale factor for the transfer function. We discuss both monochromatic and polychromatic applications of the integrated efficiency and provide examples to demonstrate its utility.
133 citations