51 research outputs found

    Encoding and Multiplexing of 2D Images with Orbital Angular Momentum Beams and the Use for Multiview Color Displays.

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    The orthogonal nature of different orbital angular momentum modes enables information transmission in optical communications with increased bandwidth through mode division multiplexing. So far the related works have been focused on using orbital angular momentum modes to encode/decode and multiplex point-based on-axis signals for maximum data channel numbers and capacity. Whether orbital angular momentum modes can be utilized to encode/decode off-axis signals for multiplexing in two-dimensional space is of significant importance both fundamentally and practically for its enormous potential in increasing the channel information capacity. In this work, a direct use of orbital angular momentum modes to encode/decode and multiplex two-dimensional images is realized in a scalable multiview display architecture, which can be utilized for viewing three-dimensional images from different angles. The effect of off-axis encoding/decoding and the resultant crosstalk between multiplexed different two-dimensional views are studied. Based on which, a color display of good image quality with four independent views is demonstrated. The resolution of the decoded images is analyzed and the limitation of this approach discussed. Moreover, a spatially multiplexed data communication scheme is also proposed with such a two-dimensional encoding/decoding approach to significantly enhance the data transmission capacity in free space for future data communication needs.UK Engineering and Physical Sciences Research Council (EPSRC) for the support through the Platform Grant for Liquid Crystal Photonics (EP/F00897X/1) and the EPSRC Centre for Innovative Manufacturing in Ultra Precision (EP/I033491/1

    Robust paths to net greenhouse gas mitigation and negative emissions via advanced biofuels

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    ACKNOWLEDGEMENTS We thank Dennis Ojima and Daniel L. Sanchez for their encouragement on this topic. The authors gratefully acknowledge partial support as follows: J.L.F., L.R.L., T.L.R., E.A.H.S., and J.J.S., the Sao Paulo Research Foundation (FAPESP grant# 2014/26767-9); J.L.F., L.R.L., K.P., and T.L.R., The Center for Bioenergy Innovation, a U.S. Department of Energy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of Science (grant# DE-AC05-00OR22725); L.R.L., the Sao Paulo Research Foundation, and the Link Foundation; J.L.F. and K.P., USDA/NIFA (grant# 2013-68005-21298 and 2017-67019-26327); T.L.R., USDA/NIFA (grant# 2012-68005-19703); D.S.L. and S.P.L., the Energy Biosciences Institute. Data availability The DayCent model (https://www2.nrel.colostate.edu/projects/daycent/) is freely available upon request. Specification of DayCent model runs and automated model initialization, calibration, scenario simulation, results analysis, and figure generation were implemented in Python 2.7, using the numpy module for data processing and the matplotlib module for figure generation. Analysis code is available in a version-controlled repository (https://github.com/johnlfield/Ecosystem_dynamics). A working copy of the code, all associated DayCent model inputs, and analysis outputs are also available in an online data repository (https://figshare.com/s/4c14ec168bd550db4bad; note this URL is for accessing a private version of the repository, and will eventually be replaced with an updated URL for the public version of the repository, which will only be accessible after the journal-specified embargo date).Peer reviewedPostprintPublisher PD

    Rapid hologram generation utilizing layer-based approach and graphic rendering for realistic three-dimensional image reconstruction by angular tiling

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    An approach of rapid hologram generation for the realistic three-dimensional (3-D) image reconstruction based on the angular tiling concept is proposed, using a new graphic rendering approach integrated with a previously developed layer-based method for hologram calculation. A 3-D object is simplified as layered cross-sectional images perpendicular to a chosen viewing direction, and our graphics rendering approach allows the incorporation of clear depth cues, occlusion, and shading in the generated holograms for angular tiling. The combination of these techniques together with parallel computing reduces the computation time of a single-view hologram for a 3-D image of extended graphics array resolution to 176 ms using a single consumer graphics processing unit card. © 2014 SPIE and IS and T

    Encoding and multiplexing of 2D images with orbital angular momentum beams and the use for multiview color displays

    No full text
    The orthogonal nature of different orbital angularmomentummodes enables information transmission in optical communications with increased bandwidth through mode division multiplexing. So far the related works have been focused on using orbital angular momentum modes to encode/decode and multiplex point-based on-axis signals for maximum data channel numbers and capacity. Whether orbital angular momentum modes can be utilized to encode/decode off-axis signals for multiplexing in twodimensional space is of significant importance both fundamentally and practically for its enormous potential in increasing the channel information capacity. In this work, a direct use of orbital angular momentum modes to encode/decode and multiplex twodimensional images is realized in a scalable multiview display architecture, which can be utilized for viewing three-dimensional images fromdifferent angles.The effect of off-axis encoding/decoding and the resultant crosstalk betweenmultiplexed different twodimensional views are studied. Based on which, a color display of good image quality with four independent views is demonstrated. The resolution of the decoded images is analyzed and the limitation of this approach discussed. Moreover, a spatially multiplexed data communication scheme is also proposed with such a two-dimensional encoding/decoding approach to significantly enhance the data transmission capacity in free space for future data communication needs

    Full bandwidth coarse integral holographic video displays with spatial tiling for scalability

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    This paper introduces full bandwidth Coarse Integral Holographic Display architecture with spatial tiling for scalability. The new method uses a large resonant scanner in conjunction with spatial tiling of spatial light modulators (SLMs) to create doubling the hologram's horizontal size and utilize the full bandwidth of the SLMs

    Bandwidth utilization improvement methods of Coarse Integral Holographic video Displays

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    This paper introduces two methods to improve the bandwidth utilization in the Coarse Integral Holographic Display architecture, achieving doubled horizontal field of view and fully utilized bandwidth for the spatial light modulator in use

    Full bandwidth dynamic coarse integral holographic displays with large field of view using a large resonant scanner and a galvanometer scanner

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    An efficient method to implement the coarse integral holographic (CIH) concept for dynamic CIH displays is to scan the information generated from a spatial light modulator (SLM) of a low space bandwidth product (SBP) but high bandwidth to form the hologram array for the integral optics. Previously, just over half of the SLMs bandwidth was utilized due to the fact that the galvanometer scanner in use could not tile all the holograms that the SLM is capable to produce, resulting in the loss of nearly half of the field of view (FOV). Here, we propose a full bandwidth dynamic CIH display using a large resonant scanner in conjunction with a hybrid raster scanner, which can utilize the full bandwidth of the spatial light modulator and double the horizontal FOV. Experimental results confirm that with the SLM and scanners as used, the FOV can reach 48° when the SLM reaches its full bandwidth. This approach can be used for future scalable and tileable CIH display systems

    Implementation of shading effect for reconstruction of smooth layerbased 3D holographic images

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    A holographic rendering algorithm using a layer-based structure with angular tiling supports view-dependent shading and accommodation cues. This approach also has the advantages of rapid computation speed and visual reduction of layer gap artefacts compared to other approaches. Holograms rendered with this algorithm are displayed using an SLM to demonstrate view-dependent shading and occlusion. © 2013 SPIE-IS&T
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