Growth and Characterization of LiNbO3 Single Crystals Doped with Cu and Fe Ions
TL;DR: In this article, single crystals of lithium niobate doped with 0.03 and 0.1% of Cu or Fe ions were grown by the Czochralski technique.
Abstract: Single crystals of lithium niobate doped with 0.03 and 0.1 at.% of Cu or Fe ions were grown by the Czochralski technique. Optical absorption spectra in visible and infrared regions before and after • irradiation with doses up to 10 5 Gy were measured and positions of both dopants in LiNbO 3 lattice were analyzed according to changes in optical absorption in the range of OH group absorption. Some properties of crystals doped with Cu during the growth processes were compared to those for specimens doped by thermodiffusion. It was observed that doping with Cu results in an increase of crystal resistance to radiation.
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01 Oct 2020
TL;DR: A review of lithium niobate single crystals and polycrystals in the form of powders has been prepared in this paper, where both the classical and recent literature on this topic are revisited.
Abstract: A review of lithium niobate single crystals and polycrystals in the form of powders has been prepared. Both the classical and recent literature on this topic are revisited. It is composed of two parts with sections. The current part discusses the earliest developments in this field. It treats in detail the basic concepts, the crystal structure, some of the established indirect methods to determine the chemical composition, and the main mechanisms that lead to the manifestation of ferroelectricity. Emphasis has been put on the powdered version of this material: methods of synthesis, the accurate determination of its chemical composition, and its role in new and potential applications are discussed. Historical remarks can be found scattered throughout this contribution. Particularly, an old conception of the crystal structure thought as a derivative structure from one of higher symmetry by generalized distortion is here revived.
23 citations
TL;DR: In this paper, Ru-doped lithium niobate (LiNbO 3 ) single crystals were grown by the Czochralski method from a congruent melt composition.
20 citations
TL;DR: In this paper, the authors reviewed two main methods for the elimination of anti-site defects: doping of metal ions and growth of stoichiometric crystals, and summarized the recent progress in theoretical and technical processes, including the improved applications.
Abstract: Lithium niobate (LiNbO3 or LN) and lithium tantalate (LiTaO3 or LT) crystals, which have been widely applied in many fields such as electro-optics, birefringence, nonlinear optics, photorefraction, piezoelectricity and other areas, are reviewed. The studies of the properties and growth techniques are reviewed to give a brief idea of the growth of LN and LT crystals with high quality. The anti-site defects of these crystal materials have been accepted as one of the key factors constraining the improvement of their properties. This review shows the simulated calculation and structure of anti-site defects in LN/LT crystals and their effect on the physical properties and summarizes the recent progress in theoretical and technical processes, including the improved applications. We reviewed two main methods for the elimination of anti-site defects: doping of metal ions and growth of stoichiometric crystals. Finally, the prospects for future studies are outlined.
15 citations
TL;DR: In this article, a triplet structure is observed for the absorption band due to the 2 E g → 2 T 2g transition in a crystal with 0.05 at.% Cu 2+ ions.
14 citations
TL;DR: In this article, the growth conditions for lithium tantalate single crystals doped with rare-earth and conditions of the diffusion process for doping with Cr and Cu are described, and absorption and an additional absorption after g-irradiation and annealing treatments at room temperature 5 were measured.
13 citations
References
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TL;DR: In this article, a single-mode low-loss waveguide which confine the guided light to within ∼1 μm of the surface has been constructed using a single transition metal (Ti, V, and Ni).
Abstract: Deposited films of transition metals (Ti, V, and Ni) have been diffused into LiNbO3 crystals to form low‐loss TE and TM mode optical waveguides Using Ti, single‐mode low‐loss waveguides which confine the guided light to within ∼1 μm of the surface have been constructed The choice of diffusion parameters allows independent control of important waveguide parameters
633 citations
TL;DR: In this article, the photorefractive properties of LiNbO3∶Fe and LiNiBO3 ∶Cu have been studied in combination with optical absorption-, Mossbauer-and EPR-measurements.
Abstract: The photorefractive properties of LiNbO3∶Fe and LiNbO3∶Cu have been studied in combination with optical absorption-, Mossbauer- and EPR-measurements. The charge states of Fe in successively reduced LiNbO3∶Fe have been investigated with respect to the influence on the photorefractive sensitivity and saturation value of the refractive index change. The results of this experiment demonstrate clearly the close correlation between the concentration of Fe2+ impurities and the optical absorption band around 2.6 eV in LiNbO3∶Fe, which is known to give rise to an anisotropic charge transport upon optical excitation. The resulting photocurrents determine the photorefractive sensitivity mainly in the initial state of halographic exposure. With increasing conversion from Fe3+ to Fe2+ the photorefractive sensitivity saturates and the saturation value of the refractive index change decreases remarkably.
254 citations
TL;DR: In this paper, a theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO/sub 3.
Abstract: 56% efficient external-cavity-resonant second-harmonic generation of a diode-laser pumped, CW single-axial-mode Nd:YAG laser is reported. A theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO/sub 3/. The best conversion efficiency was obtained with a 12.5-mm-long monolithic ring cavity doubler, which produced 29.7 mW of CW, single-axial mode 532-nm radiation from an input of 52.5 mW. >
238 citations
NGK1
TL;DR: In this paper, a double crucible Czochralski method was applied to control crystal stoichiometry during growth and to produce uniformly doped single crystals of various oxide compositions.
223 citations
TL;DR: In this article, LiNbO 3 single crystals have been grown using the top-seeded solution growth method from potassium containing flux and Spectroscopic properties (e.g., the UV absorption edge, OH-vibrational band) have been used for the characterization of the crystal composition.
210 citations
"Growth and Characterization of LiNb..." refers background in this paper
...Hence, there has been a noticeable interest in research works dealing with single-crystal growth of stoichiometric LiNbO3 (KITAMURA et al., 1992) theoretically free from lithium vacancies (POLGAR et al., 1997)....
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