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: This paper presents the first experimental demonstration on the holographic fabrication approach of three-dimensional photonic crystal templates with functional defects by a single laser exposure using a single optical element.
Abstract: This paper demonstrates an approach for laser holographic patterning of three-dimensional photonic lattice structures using a single diffractive optical element. The diffractive optical element is fabricated by recording gratings in a photosensitive polymer using a two-beam interference method and has four diffraction gratings oriented with four-fold symmetry around a central opening. Four first-order diffracted beams from the gratings and one non-diffracted central beam overlap and form a three-dimensional interference pattern. The phase of one side beam is delayed by inserting a thin piece of microscope glass slide into the beam. By rotating the glass slide, thus tuning the phase of the side beam, the five beam interference pattern changes from face-center tetragonal symmetry into diamond-like lattice symmetry with an optimal bandgap. Three-dimensional photonic crystal templates are produced in a photoresist and show the phase tuning effect for bandgap optimization. Furthermore, by integrating an amplitude mask in the central opening, line defects are produced within the photonic crystal template. This paper presents the first experimental demonstration on the holographic fabrication approach of three-dimensional photonic crystal templates with functional defects by a single laser exposure using a single optical element.
40 citations
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TL;DR: Experimental techniques are described for recording Lippmann color holograms in methylene-blue-sensitized dichromated gelatin with diffraction efficiency and wavelength selectivity.
Abstract: Experimental techniques are described for recording Lippmann color holograms in methylene-blue-sensitized dichromated gelatin. 458-, 488-, and 514.5-nm light from an argon laser and 633-nm light from a He-Ne laser are used to record the holograms. Data on the diffraction efficiency and wavelength selectivity are presented.
40 citations
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TL;DR: Both theoretical and experimental results show that the distortions of the optical pulses introduced by the reflective Dammann gratings are very small, which should be highly interesting for characterizing the ultrashort pulse.
Abstract: In this paper we propose a very simple layout of multi-shot second-harmonic-generation (SHG) frequency-resolved optical gating (FROG) using three reflective Dammann gratings ( Dammann SHG-FROG) for characterization of the ultrashort optical pulses. One reflective Dammann gratings is used as the beamsplitter and the other two compensate the angular dispersion. Both theoretical and experimental results show that the distortions of the optical pulses introduced by the reflective Dammann gratings are very small. This device should be highly interesting for characterizing the ultrashort pulse. (C) 2005 Optical Society of America.
40 citations
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TL;DR: The resonance condition of a leaky mode propagating in a dielectric multilayer, which is supported by a mirror and excited by a free-space wave from the cover medium, is derived from the phase of the reflection at the mirror and cover interfaces as discussed by the authors.
Abstract: The resonance condition of a leaky mode propagating in a dielectric multilayer, which is supported by a mirror and excited by a free-space wave from the cover medium, is simply derived from the phase of the reflection at the mirror and cover interfaces. The leaky mode resonance is used to obtain 100% first-order diffraction efficiency in a reflection resonant grating by destructive interference in the direction of Fresnel reflection. A number of examples support the validity of this condition for high efficiency and illustrate the usefulness of this intelligible representation of the diffraction phenomena for the synthesis of novel diffractive elements.
40 citations
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TL;DR: In this article, an all-optical switching effect was observed when a light beam of suitable wavelength irradiates a "layered" structure made of polymer slices alternated to films of well aligned liquid crystal (LC) which contain also a small percentage of azo-LC molecules.
Abstract: We present the observation of an all-optical switching effect that takes place when a light beam of suitable wavelength irradiates a “layered” structure made of polymer slices alternated to films of well aligned liquid crystal (LC) which contain also a small percentage of azo-LC molecules. The simple and reliable fabrication procedure exploits a holographic UV curing technique. The observed switching effect takes place in samples that exhibit diffraction efficiency as high as 85% and is induced in less than 0.5 s by an unfocused pump beam of 245 mW/cm2 power density.
39 citations