Relaxor-based ferroelectric single crystals: growth, domain engineering, characterization and applications.

Theory of electromagnetic waves : a coordinate-free approach / Hollis C. Chen

Photocontrol of molecular alignment is an exceptionally-intelligent and useful strategy. It enables us to control optical coefficients, peripheral molecular alignments, surface relief structure, and actuation of substances by means of photoirradiation. Azobenzene-containing polymers and functionalized liquid crystalline polymers are well-known photocontrollable materials. In this paper, we introduce recent applications of these materials in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics. The concepts in each application are explained based on the mechanisms of photocontrol. The interesting natures of the photocontrollable materials and the conceptual applications will stimulate novel ideas for future research and development in this field.

https://www.mdpi.com/2073-4360/4/1/150/pdf

Optical and Physical Applications of Photocontrollable Materials: Azobenzene-Containing and Liquid Crystalline Polymers

Recent advances and applications of random lasers and random fiber lasers

The recent advances in the photorefraction of doped lithium niobate crystals are reviewed. Materials have always been the main obstacle for commercial applications of photorefractive holographic storage. Though iron-doped LiNbO3 is the mainstay of holographic data storage efforts, several shortcomings, especially the low response speed, impede it from becoming a commercial recording medium. This paper reviews the photorefractive characteristics of different dopants, especially tetravalent ions, doped and co-doped LiNbO3 crystals, including Hf, Zr and Sn monodoped LiNbO3, Hf and Fe, Zr and Fe doubly doped LiNbO3, Zr, Fe and Mn, Zr, Cu and Ce triply doped LiNbO3, Ru doped LiNbO3, and V and Mo monodoped LiNbO3. Among them, Zr, Fe and Mn triply doped LiNbO3 shows excellent nonvolatile holographic storage properties, and V and Mo monodoped LiNbO3 has fast response and multi-wavelength storage characteristics.

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Recent Advances in the Photorefraction of Doped Lithium Niobate Crystals

Image formation in a collinear holographic storage system was analyzed. The wavefront from each pixel of a spatial light modulator was regarded as a plane wave in the recording medium, and its wave vector was determined by the position of the pixel. The hologram in the recording medium was treated as the summation of all gratings written by all combinations of two plane waves. The image of a data page was formed by diffraction of the reference waves by all gratings. The results of the simulation showed good agreement with experiment. We introduced the pixel spread function to describe the image formation characteristics. Analysis of the pixel spread function reveals that a radial-line pixel pattern for reference waves gave a sharper image than other reference pixel patterns. It is also shown that a random phase modulation applied to each reference pixel improved the image formation.

Analysis of a collinear holographic storage system: introduction of pixel spread function

The optical response of polarization sensitive materials is studied on the basis of a model in which the materials consist of rod molecules that are oriented in random directions. The photoinduced change of the dielectric tensor is expressed as a function of the electric field in a general form. Using this expression, we derive the vectorial coupled wave equations in volume polarization holograms. We discuss the basic properties of polarization holograms.

Theory of polarization holography

Photorefractive and photochromic properties of Ru doped Sr0.61Ba0.39Nb2O6 crystal

The photorefractive properties of the iron-doped Pb(Zn1∕3Nb2∕3)O3-PbTiO3 (PZN-PT) relaxor ferroelectric single crystals were investigated by two-beam coupling experiments The Fe:001wt%- and the Fe:01wt%-doped 091PZN-009PT single crystals were grown with the flux solution method The Extinction spectrum, the electro-opric coefficient, the light-induced absorption change, and the photoconductivity were measured in these samples The maximum gain coefficient reached to 21cm−1, which is about twice as large as that of undoped PZN-PT The grating formation rate decreases with the Fe concentration

Ryushi Fujimura

Papers

Analysis of a collinear holographic storage system: introduction of pixel spread function

Theory of polarization holography

Photorefractive and photochromic properties of Ru doped Sr0.61Ba0.39Nb2O6 crystal

Photorefractive effect and photochromism in the Fe-doped relaxor ferroelectric crystal Pb(Zn1∕3Nb2∕3)O3-PbTiO3

Two-color nonvolatile holographic recording and light-induced absorption in Ru and Fe codoped LiNbO3 crystals