Polarization holographic gratings in sp configuration are written at 488 nm in photorefractive organic-inorganic films based on SiO2. The films, prepared by a solgel technique, contain Disperse Red 1, carbazole units, and 2,4,7-trinitro-9-fluorenone. The gratings are characterized by their diffraction efficiency for a 632.8-nm probe. The polarization gratings act as a half-wave plate, and the diffraction efficiency is independent of the polarization direction of the probe.
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http://dx.doi.org/10.1364/ol.28.002240 | DOI Listing |
This Letter discusses the limitations of immersion-free recording schemes for holographic waveguide displays. Traditional holographic recording of waveguides requires recording angles exceeding the critical angle of the hologram-cladding interface. Achieving these angles necessitates edge-lit exposure using prisms and immersion liquids, which are challenging for roll-to-roll mass production and hinder widespread adoption.
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January 2025
School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, China.
Metasurfaces have exhibited excellent capabilities in controlling main characteristics of electromagnetic fields. Thus, a lot of significant achievements have been attained in many areas especially in the fields of hologram and near-field imaging. However, some of these designs are implemented in a manner of interleaved subarrays that complicates the design and makes them difficult to achieve integration.
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January 2025
Department of Electrical Engineering, Iran University of Science and Technology, Tehran, 16846-1314, Iran.
The holographic technique is one of the simplest methods for designing antennas based on metasurface. This paper presents a spoof surface plasmon polariton (SSPP) leaky-wave antenna (LWA) based on the concept of impedance modulated metasurfaces by the anisotropic holographic technique. Instead of parasitic elements, anisotropic SSPP elements are exploited to achieve radiation with circular polarization.
View Article and Find Full Text PDFJ Biophotonics
January 2025
School of Optoelectronics, Zhejiang University, Hangzhou, China.
The article describes a technique for digital holographic reconstruction of complex amplitude fields in diffuse blood facies using laser polarization-interference phase scanning to isolate a single scattered component of the object field. This method serves as the basis for developing algorithms for Mueller-matrix reconstruction of linear and circular birefringence parameters in the polycrystalline architectonics of blood facies. Statistical (central moments of the 1st-4th orders) and multifractal analyses (fractal dimension spectra) are applied to study the optical anisotropy maps of polycrystalline networks during blood dehydration.
View Article and Find Full Text PDFNano Lett
January 2025
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
The complete manipulation of Jones matrix phase-channels using metasurfaces brings forth unparalleled possibilities across diverse wavefront modulation applications. Traditionally, achieving independent control over all four phase-channels usually involves the introduction of chirality with multilayer or three-dimensional metasurfaces. Here, we present a general chirality-free method that relies on polarization base transformation with a planar minimalist metasurface, effectively decoupling the four Jones matrix phase-channels, thereby unleashing the fundamental boundaries imposed by conventional linear or circular polarization bases.
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