Compact and portable holographic camera using photorefractive crystals. Application in various metrological problems

Georges, Marc; Scauflaire, Véronique; Lemaire, Philippe

doi:10.1007/s003400100582

Cited by 64 publications

(29 citation statements)

References 3 publications

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“…In particular, the photorefractive effect is used in many technical applications of sillenites (Baade et al 2001, Buse 1997, Georges et al 2001, and single crystals of sillenite also serve as optical sensors for electric current and voltage (van den Tempel 1993, Kaneko et al 1999, Filippov et al 2000 or as surface acoustic wave guides (Lu et al 2000).…”

Section: Bimentioning

confidence: 99%

Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory

Wiehl¹,

Friedrich²,

Haussühl³

et al. 2010

J. Phys.: Condens. Matter

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The crystal structure of the bismuth silicon oxide Bi 12 SiO 20 was determined by single-crystal x-ray diffraction at ambient conditions and at high pressure. Single-crystal intensity data between 0.0001 and 16.8(3) GPa were collected in house with Mo Kα radiation and with synchrotron radiation (λ = 0.45Å) at HASYLAB (D3), while lattice parameters were measured up to 23.0(3) GPa. The large cavities which exist in the crystal structure and host the lone electron pairs of the Bi 3+ ions are considerably compressed at high pressure. The crystal structure, however, remains stable and the lone electron pair is stereochemically active up to at least 16.8 GPa. A larger compression in the direction of the lone electron pairs by shear deformation was not observed. Raman spectra of Bi 12 SiO 20 were measured on powder samples during pressure decrease from 39.1(1) GPa down to ambient pressure and on single crystals during pressure increase up to 12.50(3) GPa. Density functional perturbation theory was used to compute Raman frequencies and intensities at ambient pressure and to investigate pressure-induced changes up to 50 GPa.

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Section: Bimentioning

confidence: 99%

Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory

Wiehl¹,

Friedrich²,

Haussühl³

et al. 2010

J. Phys.: Condens. Matter

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“…The analysis of interferograms can be achieved by any of the classical technique described in the literature. A unique feature of the CSL holographic camera [7] is that it uses a photorefractive crystal to record the hologram. The latter allows in-situ recording of the hologram and is fully erasable by the readout beam itself.…”

Section: Introductionmentioning

confidence: 99%

Development of optical ground verification method for um to sub-mm reflectors

Stockman

Thizy

Lemaire

et al. 2017

International Conference on Space Optics — ICSO 2004

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Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. Scientific observatories require large telescopes with precisely shaped reflectors for collecting the electro-magnetic radiation from faint sources. The challenging tasks of on-ground testing are to achieve the required accuracy in the measurement of the reflector shapes and antenna structures and to verify their performance under simulated space conditions (vacuum, low temperatures). Due to the specific surface characteristics of reflectors operating in these spectral regions, standard optical metrology methods employed in the visible spectrum do not provide useful measurement results.The current state-of-the-art commercial metrology systems are not able to measure these types of reflectors because they have to face the measurement of shape and waviness over relatively large areas with a large deformation dynamic range and encompassing a wide range of spatial frequencies. 3-D metrology (tactile coordinate measurement) machines are generally used during the manufacturing process. Unfortunately, these instruments cannot be used in the operational environmental conditions of the reflector.The application of standard visible wavelength interferometric methods is very limited or impossible due to the large relative surface roughnesses involved. A small number of infrared interferometers have been commercially developed over the last 10 years but their applications have also been limited due to poor dynamic range and the restricted spatial resolution of their detectors. These restrictions affect also the surface error slopes that can be captured and makes their application to surfaces manufactured using CRFP honeycomb technologies rather difficult or impossible.It has therefore been considered essential, from the viewpoint of supporting future ESA exploration missions, to develop and realise suitable verification tools based on infrared interferometry and other optical techniques for testing large reflector structures, telescope configurations and their performances under simulated space conditions. Two methods and techniques are developed at CSL.The first one is an IR-phase shifting interferometer with high spatial resolution. This interferometer shall be used specifically for the verification of high precision IR, FIR and sub-mm reflector surfaces and telescopes under both ambient and thermal vacuum conditions. The second one presented hereafter is a holographic method for relative shape measurement. The holographic solution proposed makes use of a home built vacuum compatible holographic camera that allows displacement measurements from typically 20 nanometres to 25 microns in one shot. An iterative process allows the measurement of a total of up to several mm of deformation. Uniquely the system is designed to measure both specular and diffuse surfaces.

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“…has numerous technologically important applications in electro-optical, electro-mechanical, non-linear optical devices, scintillating material , media for holographic data storage displaying strong photochromic and photorefractive effects in visible spectral range [1][2][3][4][5][6]. There are a lot of studies in the literature [6][7][8] and references therein, regarding various aspects related to the divalent cobalt ions doped BGO crystals.…”

Section: Introductionmentioning

confidence: 99%

Energy levels scheme simulation of divalent cobalt doped bismuth germanate

Andreici

Petkova

Avram

2015

AIP Conference Proceedings

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Abstract. The aim of this paper is to simulate the energy levels scheme for Bismuth Germanate (BGO) doped with divalent cobalt, in order to give a reliable explanation for spectral experimental data. In the semiempirical crystal field theory we first modeled the Crystal Field Parameters (CFPs) of BGO:Cr 2+ system, in the frame of Exchange Charge Model (ECM), with actually site symmetry of the impurity ions after doping. The values of CFPs depend on the geometry of doped host matrix and by parameter G of ECM. First, we optimized the geometry of undoped BGO host matrix and afterwards, that of doped BGO with divalent cobalt. The charges effect of ligands and covalence bonding between cobalt cations and oxygen anions, in the cluster approach, also were taken into account. With the obtained values of the CFPs we simulate the energy levels scheme of cobalt ions, by diagonalizing the matrix of the doped crystal Hamiltonian. Obviously, energy levels and estimated Racah parameters B and C were compared with the experimental spectroscopic data and discussed. Comparison of obtained results with experimental data shows quite satisfactory, which justify the model and simulation schemes used for the title system.

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Compact and portable holographic camera using photorefractive crystals. Application in various metrological problems

Cited by 64 publications

References 3 publications

Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory

Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory

Development of optical ground verification method for um to sub-mm reflectors

Energy levels scheme simulation of divalent cobalt doped bismuth germanate

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Compact and portable holographic camera using photorefractive crystals. Application in various metrological problems

Cited by 64 publications

References 3 publications

Structural compression and vibrational properties of Bi12SiO20sillenite from experiment and theory

Structural compression and vibrational properties of Bi12SiO20sillenite from experiment and theory

Development of optical ground verification method for um to sub-mm reflectors

Energy levels scheme simulation of divalent cobalt doped bismuth germanate

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Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory

Structural compression and vibrational properties of Bi₁₂SiO₂₀sillenite from experiment and theory