elektronika: Diffraction grating

Evidence: 100 • authority: 72

In optics, a diffraction grating is a grating with a periodic structure of appropriate scale so as to diffract light, or another type of electromagnetic radiation, into several beams traveling in different directions (i.e., different diffraction angles) known as diffracted orders. The emerging coloration is a form of structural coloration. The directions or diffraction angles of these beams depend on the wave (light) incident angle to the diffraction grating, the spacing or periodic distance between adjacent diffracting elements (e.g., parallel slits for a transmission grating) on the grating, and the wavelength of the incident light. Because the grating acts as a dispersive element, diffra…

Evidence: 45 • authority: 88

Resonance anomalies of dielectric-layered diffraction gratings for TE and TM polarized incident waves. Grating anomalies are natural phenomena associated with diffraction gratings. Three categories are defined to distinguish the different types of anomaly: Rayleigh wavelength, resonance, and surface plasmon. In this paper, the guided-mode resonance characteristics of dielectric waveguide diffraction gratings are studied by the rigorous coupled-wave theory. For weakly modulated gratings, it is shown that elementary waveguide theory can be used to locate the resonances and define associated parametric ranges. It is also shown that the transverse field equation describing the field distributio…

Evidence: 45 • authority: 88

Diffraction Analysis of Multiplexed Holographie Gratings. Optical diffraction by periodic structures are of increasing importance in an expanding variety of engineering applications [1]. Diffraction of electromagnetic waves by spatially periodic media has been analyzed by numerous authors over the last fifty years [1]. In almost all previous analyses, only diffractive structure with one single grating (and its harmonics) were considered. Recent applications for holographic optical elements include associative storage, optical computing, multiple holographic storage, beam coding, multiple beam generation and combining, multi-color displays, multi-color filtering, beam shaping, synthetic lens…

Evidence: 38 • authority: 92

Information multiplexing from optical holography to multi-channel metaholography.. Holography offers a vital platform for optical information storage and processing, which has a profound impact on many photonic applications, including 3D displays, LiDAR, optical encryption, and artificial intelligence. In this review, we provide a comprehensive overview of optical holography, moving from volume holography based on optically thick holograms to digital holography using ultrathin metasurface holograms in nanophotonics. We review the use of volume holograms for holographic multiplexing through the linear momentum selectivity and other approaches and highlight the emerging use of digital hologra…

Evidence: — • authority: 80

Phase-matched concatenation of fiber Bragg gratings using the anti -phase amplitude modulation experienced by the inscription UV beams after diffraction by the gratings

Evidence: — • authority: 72

Digital holography is the acquisition and processing of holograms from a digital sensor array, typically a CCD camera or a similar device, and also refers to the display of holograms using a digital output device such as a spatial light modulator. Image rendering, or reconstruction of object data is performed numerically from digitized interferograms. Digital holography offers a means of measuring optical phase data and typically delivers three-dimensional surface or optical thickness images. Several recording and processing schemes have been developed to assess optical wave characteristics such as amplitude, phase, and polarization state, which make digital holography a very powerful metho…