Investigation of optical homogeneity and photorefractive properties of lithium-niobate single crystals by the Raman-spectroscopy and laser-conoscopy methods

Interference patterns of single crystals of LiNbO3:Gd, LiNbO3:Er, obtained by laser conoscopy, allow us to estimate the optical homogeneity of the samples under study. The observation of conoscopic patterns of the LiNbO3:Gd single crystal shows that with an increase in the percentage impurity concentration, the anomalous biaxiality in these samples manifests itself to a much greater degree. Anomalous biaxiality for the sample LiNbO3:Er [3.60 wt.%] is present at almost every point of the entrance face, which is manifested in conoscopic patterns in the form of enlightenment and rupture of the “Maltese cross”, which corresponds to the angle 2V~1° between the anomalous axes.

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Structural particularities and optical properties of lithium niobate single crystals grown from the charge doped by boron.

Transaction Kola Science Cetnre ◽

10.37614/2307-5252.2020.3.4.041 ◽

2020 ◽

Vol 11 (3-2020) ◽

pp. 189-195

Author(s):

R. A. Titov ◽

◽

N. V. Sidorov ◽

N. A. Teplyakova ◽

M. N. Palatnikov ◽

...

Keyword(s):

Optical Properties ◽

Light Scattering ◽

Lithium Niobate ◽

Distribution Coefficient ◽

Single Crystals ◽

Infrared Absorption ◽

Cation Sublattice ◽

Structural Units ◽

Photoinduced Light Scattering ◽

Laser Conoscopy

The analysis of structural particularities and optical properties of LiNbO3 : B (0,55, 0,69 and 0,83 mol. % B2O3) was performed by methods of Raman and photoinduced light scattering, infrared absorption and laser conoscopy. It has been established that the boron impurity brings to 1 the distribution coefficient of lithium and niobium in the growing process. Thus, LiNbO3: B crystals grown from a congruent melt approach the stoichiometric crystals in ordering the structural units of the cation sublattice and the Li / Nb ratio.

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Visualization of Optical Uniformity Alloyed Single Crystals of Lithium Niobate

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.312.140 ◽

2020 ◽

Vol 312 ◽

pp. 140-147

Author(s):

Olga Y. Pikoul ◽

Nikolay V. Sidorov ◽

Natalya A. Teplyakova ◽

Mikhail N. Palatnikov

Keyword(s):

Lithium Niobate ◽

Single Crystals ◽

Mechanical Stresses ◽

Field Of View ◽

Local Change ◽

Defective Structure ◽

Maltese Cross ◽

Peripheral Area ◽

Laser Conoscopy ◽

Elastic Characteristics

It was shown that laser conoscopy can visually detect even slight changes in the optical characteristics of a crystal when it is doped. It has been found that the defective structure of LiNbO3:Zn (4.5 mol. %), LiNbO3:Mg (3.0–5.5 mol.%) crystals associated with an uneven entry of an impurity leads to a local change in the elastic characteristics of the crystal and the appearance of mechanical stresses that distort the conoscopic patterns. This can be an abnormal optical biaxiality, which manifests itself in the form of a rupture and enlightenment of the "Maltese cross" in the center of the conoscopic crystal pattern, or local birefringent inclusions that are recorded as additional interference patterns against the background of the main conoscopic pattern, both in the center of the field of view and in its peripheral area.

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Visualization of the Effect of an Impurity on the Optical Homogeneity of Lithium Niobate Doped with Boron Cations

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.887.65 ◽

2021 ◽

Vol 887 ◽

pp. 65-70

Author(s):

O. Pikoul ◽

Nikolay V. Sidorov ◽

Mikhail N. Palatnikov

Keyword(s):

Lithium Niobate ◽

Laser Power ◽

Optical Homogeneity ◽

Maximum Value ◽

Optical Axes ◽

Laser Conoscopy ◽

Boron Cations

The laser conoscopy method confirms the high optical uniformity of LiNbO3:B crystals in the range of B2O3 concentrations from 0.008 to 1.24 mol. %. Minor signs of anomalous optical biaxiality appear in the conoscopic patterns of crystals at boron concentrations of 0.12 and 0.83 mol. % at a laser power of 90 mW. The maximum value of the angle of anomalous optical axes for the studied samples is 2V = 10 ́ for the sample (0.12 mol. %), аnd the value of anomalous birefringence corresponds to ∆n = 0.02·10-5.

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Raman spectroscopy and X-ray diffraction of lithium niobate at temperatures up to 1300○-4.80pt○C

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2005126021 ◽

2005 ◽

Vol 126 ◽

pp. 101-105 ◽

Cited By ~ 1

Author(s):

B. Moulin ◽

L. Hennet ◽

D. Thiaudière ◽

P. Melin ◽

P. Simon

Keyword(s):

Raman Spectroscopy ◽

Lithium Niobate ◽

X Ray Diffraction ◽

X Ray

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Flux Method Growth of Large Size Group IV–V 2D GeP Single Crystals and Photoresponse Application

Crystals ◽

10.3390/cryst11030235 ◽

2021 ◽

Vol 11 (3) ◽

pp. 235

Author(s):

Shuqi Zhao ◽

Tongtong Yu ◽

Ziming Wang ◽

Shilei Wang ◽

Limei Wei ◽

...

Keyword(s):

Raman Spectroscopy ◽

Single Crystals ◽

High Performance ◽

Group Iv ◽

X Ray Diffraction ◽

High Quality ◽

Practical Applications ◽

Large Size ◽

Growth Method ◽

Polarized Raman

Two-dimensional (2D) materials driven by their unique electronic and optoelectronic properties have opened up possibilities for their various applications. The large and high-quality single crystals are essential to fabricate high-performance 2D devices for practical applications. Herein, IV-V 2D GeP single crystals with high-quality and large size of 20 × 15 × 5 mm3 were successfully grown by the Bi flux growth method. The crystalline quality of GeP was confirmed by high-resolution X-ray diffraction (HRXRD), Laue diffraction, electron probe microanalysis (EPMA) and Raman spectroscopy. Additionally, intrinsic anisotropic optical properties were investigated by angle-resolved polarized Raman spectroscopy (ARPRS) and transmission spectra in detail. Furthermore, we fabricated high-performance photodetectors based on GeP, presenting a relatively large photocurrent over 3 mA. More generally, our results will significantly contribute the GeP crystal to the wide optoelectronic applications.

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