Real-time Holographic Recording Research Articles

Compact self-interference incoherent digital holographic camera system with real-time operation.

The video recording-capable compact incoherent digital holographic camera system is proposed. The system consists of the linear polarizer, convex lens, geometric phase lens, and the polarized image sensor. The Fresnel hologram is recorded by this simple configuration in real time. The system parameters are analyzed and evaluated to record a better-quality hologram in a compact form-factor. The real-time holographic recording and its digitally reconstructed video playback are demonstrated with the proposed system.

Near-infrared properties of Rh-doped Bi_12TiO_20crystals for photonic applications

The effect of Rh doping in Bi(12)TiO(20) (BTO) crystals on the photosensitivity and recording speed at 1064 nm is reported. Response time of 0.1 s is measured during real-time holographic recording without any preliminary treatments. Once the crystal is pre-excited with a green light, the detected response time becomes 0.02 s. A possibility to implement BTO:Rh crystal plate with liquid crystals into a hybrid organic/inorganic device is demonstrated, which opens perspectives for further near-infrared applications.

Real-time holography in ruthenium-doped bismuth sillenite crystals at 1064 nm

Real-time holographic recording and an improvement of the response time in ruthenium (Ru)-doped Bi(12)SiO(20) (BSO) crystal at 1064 nm is obtained. Using green light pre-exposure, a significant operation speed of 60 ms is achieved. In addition, the ability for image reconstruction is demonstrated in Ru-doped BSO, supporting further applications as reversible media for real-time image processing at the near-IR spectral range.

On the fundamentals of optical scanning holography

Optical scanning holography is a real-time holographic recording technique in which holographic information about a three-dimensional (3D) object is acquired using a single two-dimensional active optical scan. Applications of the technique include optical scanning microscopy, pattern recognition, 3D holographic display, and optical remote sensing. This paper introduces the basics of optical scanning holography.

Incoherent-to-coherent image converter based on hybrid liquid crystal — photoconducting polymer structure

It has been shown that the layer of nematic liquid crystal, when situated between a pair of transparent electrodes and a polymeric photoconducting layer, can serve as an efficient real-time holographic recording medium. The mutual action of DC biasing field and a space charge field generated by a spatially modulated incoming light in a photoconducting polymer is able to produce respective refractive index modulation in the liquid crystal due to molecular reorientation process. In this work, we demonstrate how, using a non-degenerate three-wave mixing technique, an optical image superimposed on one laser beam (Argon ion laser, λ=514 nm) can be transferred to another laser beam (frequency doubled Nd:YAG, λ=532 nm). The two laser light sources are mutually incoherent. Such a transfer is possible when both excitation light wavelengths are capable of charge carrier photogeneration process in photoconducting polymer (here, we used a 100-nm thick layer of copolymer of 3-octylthiophene and DR1-substituted thiophene). We report measurements of diffraction efficiency for the system studied in a function of an applied voltage and a light intensity of the incident beams.

Experimental investigation of the nonlinear optical response in Fe:PVA

Polymer materials are of growing interest for the optical data processing technologies. There are potential applications as permanent and transient data storage materials or as basic materials for the fabrication of the active and passive light guides [1–3]. The metal ion doped polymers represent a new class of organic materials for the nonlinear optics. Among such materials, the ferric chloride doped polyvinyl alcohol (Fe:PVA) and the dichromate polyvinyl alcohol (DCPVA) seem to be suitable materials for real time holographic recording [1]. Although their optical performances have been partially analysed, only a little information is available on the physics of the mechanism for the light induced change of the refractive index. Our previous papers [4–6] proposed a mechanism based on the modifications in the valence state of the metal ion. This paper relates the optical parameters to the Fe2+ contents. Optical, m-line and Mossbauer spectroscopy were used as complementary techniques relating the optical and the local parameters.

Article

Dichromated poly(acrylic acid) (DCPAA) has been used as real time holographic recording material. We report here the photochemical behavior of DCPAA when irradiated under conditions representative of those used for hologram recording. Under UV-vis spectroscopy a photoredox process (CrVI –> CrIII) was observed whose efficiency depends on the presence of dimethylformamide (DMF) used as an electron donor. ESR spectroscopy upon irradiation permits detection of the formation of Cr(V) of photochemical origin. We also identified chromium(V) of thermal origin (in the dark), organic macroradicals, and chromium(III). The formation of CO2 and carboxylate ions was clearly shown by IR spectroscopy. The photoreaction is assumed to go through an acido-basic reaction between dichromate in the excited state and poly(acrylic acid). The resulting unstable chromium polyacrylate undergoes a redox process that gives rise to chromium(V) and a macroradical R-COO• from which CO2 is formed. The presence of DMF (10% by volume) makes the overall reaction faster by a factor of approximately 3.5-4. The similar shape of the curves giving chromium(V) formation as a function of irradiation time and the curves giving the diffraction efficiencies of the hologram recorded in DCPAA as a function of exposure energy, with and without DMF, strongly argues in favor of a direct involvement of chromium(V) in the quality of the resulting hologram.Key words: holography, dichromated poly(acrylic acid), dimethylformamide, chromium.

Real-time dynamic polarization holographic recording on auto-erasable azo-dye doped PMMA storage media

Dynamic real-time holographic recording under linear cross-polarized writing beams at 488 nm was performed on two different new azo-dye doped PMMA matrices of 10±1 μm thick. For comparison, the holographic recording has also been performed under unpolarized light ( λ = 488 nm). Maximum diffraction efficiency of 0.15%, 0.20% and 5%, corresponding respectively to the x-, i-polarized and unpolarized writing beams, has been achieved. Numerous complete Write/Read/Erase (WRE) cycles have also been performed without any apparent fatigue in the recording performance of the materials. In polarization holography, a slight memory effect could be observed in both these recording materials if the time interval between two successive exposure is relatively short (2–5 s), on attempting to place a maximum number of WRE cycles in a specific time period (7–8 complete WRE cycles in 50 s).

Xanthene dye sensitized dichromated poly(vinyl alcohol) recording materials: holographic characterization and ESR spectroscopic study

Dichromated poly(vinyl alcohol)-xanthene dye (DCPVA-XD) systems have been employed as real-time holographic recording materials. Holographic performance of the undeveloped and developed dichromated poly(vinyl alcohol) (DCPVA) films with three different xanthene dyes (XD) namely fluorescein (Fl), eosin Y (EY) and rose bengal (RB) are evaluated through diffraction efficiency profiles. In addition, a systematic electron spin resonance (ESR) spectroscopic investigation was also performed on these systems to study the mechanism of holographic recording and observe the influence of XD in the photoprocesses. The photochemical evolution of Cr v, Cr III, polymer radical and dye radical in these systems has been monitored and a suitable xanthene dye photosensitized mechanism is proposed.

Real-time holographic recording of reflection gratings in a photopolymerisable composite

Real-time formation of highly efficient (up to 90%) reflection gratings in a photopolymerisable composite FPK-488 was achieved for the first time.

Polymer waveguides: characterization through prism–film coupler method

Cr(VI) and Fe(III) doped polyvinyl alcohol) and poly(acrylic acid) polymers have been used as real-time holographic recording media as well as materials to fabricate planar waveguides. Planar wave guides were made of these metal ion doped polymer thin films. Changes in the absorption spectra of these polymer films due to irradiation with an intense illumination of 468 nm light were observed. Modifications in optical properties of dichromated poly(vinyl alcohol) (DCPVA), dichromated poly(acrylic acid) (DCPAA), and ferric chloride doped polyvinyl alcohol) (FePVA) were experimentally determined by the prism–film coupler (PFC) method for the first time. Changes in the refractive index at 632.8 nm were monitored for different exposure energies. Modification of the modal properties was observed and the refractive index of these films was also determined from the angular position of the guided modes. Optical losses in both exposed and unexposed films of DCPVA, DCPAA, and FePVA were measured employing a coupling set-up with two prisms. Observed results suggest that these materials can find successful applications in promising areas like integrated optics and planar optical interconnects.

Holographic recording and all-optical modulation in photochromic polymers

Polymers doped with photochromic spirooxazine and spiropyran dyes have been investigated for real-time holographic recording. The temporal holographic response was found to depend strongly on optical recording configurations and on the recording beam intensities. The exposure sensitivities that were required for maximal diffraction efficiency were 250 mJ/cm2 for the polymers doped with spirooxazine and 650 mJ/cm2 for those doped with spiropyran. All-optical modulation of the holographic gratings with 2000 lines/mm is possible by modulation of a separate excitation beam of incoherent UV radiation. The modulated gratings can be stored for relatively long times or erased immediately.

Primary photoprocesses of chromium(VI) in real-time holographic recording material: dichromated poly(vinyl alcohol)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPrimary photoprocesses of chromium(VI) in real-time holographic recording material: dichromated poly(vinyl alcohol)Gurusamy Manivannan, Rupak Changkakoti, Roger A. Lessard, Gilles Mailhot, and Michele BolteCite this: J. Phys. Chem. 1993, 97, 28, 7228–7233Publication Date (Print):July 1, 1993Publication History Published online1 May 2002Published inissue 1 July 1993https://doi.org/10.1021/j100130a017RIGHTS & PERMISSIONSArticle Views143Altmetric-Citations44LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (741 KB) Get e-Alerts

Cr(VI)- and Fe(III)-doped polymer systems as real-time holographic recording materials

Volume transmission holograms have been recorded in dichromated poly(vinyl alcohol) (DCPVA), dichromated poly(acrylic acid) (DCPAA), and ferric chloride poly(vinyl alcohol) (FePVA) films using a 488-nm light (from an argon-ion laser), and the hologram development has been monitored in real time using a 647-nm line of the krypton laser. The influence of different chemical parameters (e.g., pH and electron donor) on the holographic efficiency has been determined, and an efficiency value as high as 70% was achieved in all three recording media. Further, the possible primary photoprocesses responsible for the hologram formation are tentatively identified and discussed

Dye-doped polyvinyl alcohol recording materials for holography and nonlinear optics

Photo-induced cross-linking polymers offer excellent properties, such as ease of handling, low cost, and real-time recording, for the application of holography and nonlinear optics. A vinyl polymer, namely, polyvinyl alcohol (PVA), has been chosen as a host matrix and is employed for holographic recording and nonlinear optics. Significant results of our experimental investigations on recording media fabricated by doping PVA with azo dyes and rhodamine 6G for real-time holographic recording and nonlinear optics are reported. The evaluation of third-order nonlinearities of azo dye/PVA systems and the characteristics of chrysoidine/PVA as a nonlinear waveguide are presented. Also, degenerate four-wave mixing experiments using a novel geometry have been carried out in rhodamine 6G/PVA films.

Real-time Reconstruction of Scanned Optical Holograms Using an Electron Beam Addressed Spatial Light Modulator

Real-time holographic recording has recently been demonstrated (1990, Jpn J. appl. Phys., 29 L1840) using the optical heterodyne scanning technique proposed by Poon (1985, Jp. Opt. Soc. Am. A, 2 521). In this paper we discuss the reconstruction of holograms generated by the heterodyne scanning technique. The primary concentration is on real-time reconstruction using an electron beam addressed spatial light modulator (EBSLM). For comparison, coherent reconstruction methods are also presented. Additional topics to be addressed are the spatial frequency limitations of the EBSLM and the derivation of the incoherent point spread function (PSF) of the holographic imaging system. Based upon the derived PSF, the reconstructed real image of a simple slit object is formulated and compared with experimental observations. Descriptions of the scanning holographic recording technique and the operation of the EBSLM are also presented.

Dichromated polyvinyl alcohol films used as a novel polarization real time holographic recording material

Real time recording and reading of volume transmission holograms were performed with dichromated polyvinyl alcohol thin solid films (31 microm) that were easy to prepare and use. Real time holograms of high diffraction efficiency were produced without any chemical development, but these films were not erasable. The present holographic study of dichromated polyvinyl alcohol films permits the consideration of many engineering applications.

Optical aberration correction by real-time holography in liquid crystals

We present results of experiments that use nematic-phase liquid crystal as a real-time holographic recording medium. Plane-wave gratings were written with as little as 10 mJ/cm(2) of incident write-beam energy from a pulsed Nd:YAG laser, and diffraction efficiencies greater than 25% were measured at 633 nm. Grating decay times were observed to fall within two distinct time regimes: a rapid-decay time of 60 to 100 microsec and a slower-decay time of 6 to 30 msec. The rapid-decay regime was used to demonstrate real-time correction of severely aberrated images by degenerate four-wave mixing.

Multiplexed permanent and real time holographic recording in photorefractive BSO

We report permanent hologram recording in crystals of photorefractive bismuth silicon oxide using reversible photochromic effects. At a recording wavelength of 488 nm, exposures of several minutes produce areas of faint discoloration in which the permanent hologram is stored. The normal photorefractive behavior is unaffected, however, permitting spatial multiplexing of both real time and permanent holograms. Experimental results and characteristics of this permanent recording in combination with the photorefractive process are presented.

Thermal gratings written in glycerol with CO_2 laser radiation

Real time holographic recording has been performed in glycerol using CO(2) laser beams for the writing. The dynamics of the grating formation was monitored with a reading beam at 632.8 nm. Particular attention has been paid on temporal behavior.