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5130 KiB

Open AccessArticle

Effects of Changing Substituents on the Non-Linear Optical Properties of Two Coumarin Derivatives

by Basílio Baseia, Francisco A. P. Osório, Larissa Ferreira Lima and Clodoaldo Valverde

Crystals 2017, 7(6), 158; https://doi.org/10.3390/cryst7060158 - 27 May 2017

Cited by 25 | Viewed by 4388

Abstract

In this article, we study the electric properties of two coumarin derivatives whose difference stems from the change of substituents at 3-position of the pendant benzene ring (

C_{18} H_{15} {NO}_{3}

) and ( [...] Read more.

In this article, we study the electric properties of two coumarin derivatives whose difference stems from the change of substituents at 3-position of the pendant benzene ring (

C_{18} H_{15} {NO}_{3}

) and (

C_{18} H_{15} {NO}_{4}

). We use the supermolecule approach to deal with the molecules under the effect of the crystalline environment to calculate dipole moment, linear polarizability, and second-order hyperpolarizability, for the isolated and embedded molecules, including the static and dynamic cases and the presence of solvents. The (hyper) polarizabilities were derived from an iterative process and an ab initio computational procedure. In addition, we also calculated the HOMO-LUMO energies; at this point, the objective is to verify the effect of the exchange of substituents on the Band-Gap energy, an important parameter related to the excitation properties of coumarin compounds. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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2914 KiB

Open AccessArticle

Synthesis, Crystal Structure and Nonlinear Optical Property of RbHgI₃

by Yanjun Li, Yuxun Ding, Yaming Li, Hongming Liu, Xianggao Meng, Ye Cong, Jiang Zhang, Xuanke Li, Xingguo Chen and Jingui Qin

Crystals 2017, 7(5), 148; https://doi.org/10.3390/cryst7050148 - 22 May 2017

Cited by 12 | Viewed by 5887

Abstract

Searching for new nonlinear optical (NLO) crystals to be used in the infrared (IR) region is still a challenge. This paper presents the synthesis, crystal structure and properties of a new halide, RbHgI₃. Its non-centrosymmetric single crystal can be grown in [...] Read more.

Searching for new nonlinear optical (NLO) crystals to be used in the infrared (IR) region is still a challenge. This paper presents the synthesis, crystal structure and properties of a new halide, RbHgI₃. Its non-centrosymmetric single crystal can be grown in solution. In its crystal structure, all the polar [HgI₄]²⁻ groups align in such a way that brings a favorable net polarization. The measurement by Kurtz–Perry powder technique indicates that RbHgI₃ shows a phase-matchable second harmonic generation (SHG) property seven times stronger than that of KH₂PO₄ (KDP). RbHgI₃ displays excellent transparency in the range of 0.48–25 μm with relatively good thermal stability. The UV absorption implies that this yellow compound’s band gap is about 2.56 eV, close to that of AgGaS₂. A preliminary measurement indicates that the laser-induced damage threshold of the crystal is about 28.3 MW/cm². These preliminary experimental data reveal that RbHgI₃ is a new candidate as nonlinear optical material in the infrared region. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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4591 KiB

Open AccessArticle

Comparative Interrelationship of the Structural, Nonlinear-Optical and Other Acentric Properties for Oxide, Borate and Carbonate Crystals

by Boris I. Kidyarov

Crystals 2017, 7(4), 109; https://doi.org/10.3390/cryst7040109 - 12 Apr 2017

Cited by 13 | Viewed by 5967

Abstract

The structure and the maximal nonlinear optical (NLO) susceptibility χ⁽²⁾ are tabulated for more 700 acentric binary oxides, 220 crystals of simple, binary and complex borates and for the same set of 110 carbonates, tartrates, formates, oxalates, acetates and fluoride-carbonates used in [...] Read more.

The structure and the maximal nonlinear optical (NLO) susceptibility χ⁽²⁾ are tabulated for more 700 acentric binary oxides, 220 crystals of simple, binary and complex borates and for the same set of 110 carbonates, tartrates, formates, oxalates, acetates and fluoride-carbonates used in ultraviolet and deep ultraviolet optoelectronics. According to the chemical formula, the structural symbols of these crystals have been plotted on the plane of two minimal oxide bond lengths (OBL). It is shown that acentric crystals are positioned on such plane inside the vertical, horizontal and slope intersected ellipses of “acentricity”. The oxide and borate crystals with moderate NLO susceptibility are found in the central parts of these ellipses intersection and, with low susceptibility, on top, at the bottom and border of the ellipses rosette. The nonpolar fluoride-carbonate crystals with high NLO susceptibility are found in the curve-side rhombic parts of the slope ellipse of “acentricity”. The unmonotonous fuzzy dependence “χ⁽²⁾” on the OBL of these crystals is observed, and their clear-cut taxonomy on compounds with π– or σ–oxide bonds is also established. It is shown that the correlations of χ⁽²⁾ with other acentric properties are nonlinear for the whole set of the oxide crystals having their clear maximum at a certain value of the piezoelectric or electro-optic coefficient. The correlation “hardness–thermoconductivity-fusibility” is plotted for oxide crystals, part of which is used at the creation of self-frequency-doubling solid state lasers. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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2684 KiB

Open AccessArticle

Structure and Optical Properties of K_0.67Rb_1.33Al₂B₂O₇ Crystal

by Qian Huang, Lijuan Liu, Mingjun Xia, Yi Yang, Shu Guo, Xiaoyang Wang, Zheshuai Lin and Chuangtian Chen

Crystals 2017, 7(4), 104; https://doi.org/10.3390/cryst7040104 - 7 Apr 2017

Cited by 3 | Viewed by 4191

Abstract

A UV nonlinear optical (NLO) crystal K_0.67Rb_1.33Al₂B₂O₇ (KRABO) has been obtained by the top-seeded solution growth method for the first time. Its structure is formed of coplanar [BO₃]³⁻ triangle groups and [...] Read more.

A UV nonlinear optical (NLO) crystal K_0.67Rb_1.33Al₂B₂O₇ (KRABO) has been obtained by the top-seeded solution growth method for the first time. Its structure is formed of coplanar [BO₃]³⁻ triangle groups and [Al₂O₇]⁸⁻ groups, which are built from two [AlO₄]⁵⁻ tetrahedra sharing one vertex. Rb and K atoms have the same coordinates and locate between each layer in a disorderly fashion. The crystal has a larger NLO effect compared with its analog K₂Al₂B₂O₇ (KABO), as evidenced by powder second harmonic generation (SHG) test. The shortest SHG phase-matching wavelength is down to 231 nm according to the first-principle calculation, which indicates that KRABO is possible for the fourth harmonic generation of Nd:YAG at 266 nm. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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2403 KiB

Open AccessArticle

Growth of High Quality Al-Doped CsLiB₆O₁₀ Crystals Using Cs₂O-Li₂O-MoO₃ Fluxes

by Xianchao Zhu, Heng Tu, Ying Zhao and Zhanggui Hu

Crystals 2017, 7(3), 83; https://doi.org/10.3390/cryst7030083 - 13 Mar 2017

Cited by 5 | Viewed by 5220

Abstract

Abstract: High quality and large size Al-doped CsLiB₆O₁₀ (CLBO) single crystals have been successfully grown by top-seeded solution growth (TSSG) technique using Cs₂O–Li₂O–MoO₃ fluxes. The advantages of this newly developed flux system were investigated by [...] Read more.

Abstract: High quality and large size Al-doped CsLiB₆O₁₀ (CLBO) single crystals have been successfully grown by top-seeded solution growth (TSSG) technique using Cs₂O–Li₂O–MoO₃ fluxes. The advantages of this newly developed flux system were investigated by viscosity measurements and growth experiments. Al-doped CLBO presents a very high transmittance in the visible region and the weak absorption values at 1064 nm along a and c axes are only 140 and 50 ppm/cm, respectively. The measured LIDT of Al-doped CLBO at λ = 1064 nm and τ = 5.0 ns is 5.10 GW/cm². Moreover, Al-doped CLBO exhibits an apparent enhancement of the hygroscopic nature in contrast with the undoped crystal as determined by the humidity experiments. Finally, a high fourth harmonic generation (FHG) conversion efficiency of 63% utilizing Al-doped CLBO has been achieved by a picosecond mode-locked Nd:YAG laser, the results also reveal that Al doping has no obvious impact on the FHG conversion efficiency. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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1497 KiB

Open AccessArticle

Temperature-Dependent Sellmeier Equations of IR Nonlinear Optical Crystal BaGa₄Se₇

by Naixia Zhai, Chao Li, Bo Xu, Lei Bai, Jiyong Yao, Guochun Zhang, Zhanggui Hu and Yicheng Wu

Crystals 2017, 7(3), 62; https://doi.org/10.3390/cryst7030062 - 23 Feb 2017

Cited by 21 | Viewed by 6202

Abstract

The thermal dependent principal refractive indices of a new promising IR nonlinear optical crystal BaGa₄Se₇ at wavelengths of 0.546, 0.5806, 0.644, 0.7065, 1.530, 1.970, and 2.325μm were measured by using the vertical incidence method within the temperature range from 25 [...] Read more.

The thermal dependent principal refractive indices of a new promising IR nonlinear optical crystal BaGa₄Se₇ at wavelengths of 0.546, 0.5806, 0.644, 0.7065, 1.530, 1.970, and 2.325μm were measured by using the vertical incidence method within the temperature range from 25 to 150 °C. We derived equations of thermal refractive index coefficients as a function of wavelength that could be used to calculate the principal thermal refractive indices at different wavelengths. The temperature-dependent Sellmeier equations were also obtained and used to calculate the phase matching angles for the optical parametric process of BaGa₄Se₇ crystal at different temperatures. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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3010 KiB

Open AccessArticle

Synthesis, Crystal Structure, and Nonlinear Optical Properties of a New Alkali and Alkaline Earth Metal Carbonate RbNa₅Ca₅(CO₃)₈

by Qiaoling Chen and Min Luo

Crystals 2017, 7(1), 10; https://doi.org/10.3390/cryst7010010 - 31 Dec 2016

Cited by 10 | Viewed by 6083

Abstract

A new nonlinear optical (NLO) material, RbNa₅Ca₅(CO₃)₈, has been synthesized by the hydrothermal method. The crystal structure is established by single-crystal X-ray diffraction. RbNa₅Ca₅(CO₃)₈ crystallizes in the hexagonal [...] Read more.

A new nonlinear optical (NLO) material, RbNa₅Ca₅(CO₃)₈, has been synthesized by the hydrothermal method. The crystal structure is established by single-crystal X-ray diffraction. RbNa₅Ca₅(CO₃)₈ crystallizes in the hexagonal crystal system with space group P6₃mc (No. 186). The structure of RbNa₅Ca₅(CO₃)₈ can be described as the adjacent infinite [CaCO₃]_∞ layers lying in the a-b plane bridged through standing-on-edge [CO₃] groups by sharing O atoms (two-fold coordinated) to build a framework with four types of tunnels running through the b-axis. The Rb, Na, and [Na_0.67Ca_0.33] atoms reside in these tunnels, respectively. The measurement of second harmonic generation (SHG) indicated that RbNa₅Ca₅(CO₃)₈ is a phase-matchable material, which had SHG responses of approximately 1×KH₂PO₄ (KDP). Meanwhile, the results from the UV-VIS diffuse reflectance spectroscopy study of the powder samples indicated that the UV cut-off edges of RbNa₅Ca₅(CO₃)₈ is about 203 nm. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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Review

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8321 KiB

Open AccessReview

Borate-Based Ultraviolet and Deep-Ultraviolet Nonlinear Optical Crystals

by Yi Yang, Xingxing Jiang, Zheshuai Lin and Yicheng Wu

Crystals 2017, 7(4), 95; https://doi.org/10.3390/cryst7040095 - 25 Mar 2017

Cited by 46 | Viewed by 8026

Abstract

Borates have long been recognized as a very important family of nonlinear optical (NLO) crystals, and have been widely used in the laser frequency-converting technology in ultraviolet (UV) and deep-ultraviolet (DUV) regions. In this work, the borate-based UV and DUV NLO crystals discovered [...] Read more.

Borates have long been recognized as a very important family of nonlinear optical (NLO) crystals, and have been widely used in the laser frequency-converting technology in ultraviolet (UV) and deep-ultraviolet (DUV) regions. In this work, the borate-based UV and DUV NLO crystals discovered in the recent decade are reviewed, and the structure–property relationship in the representative borate-based UV and DUV NLO crystals is analyzed. It is concluded that the optical properties of these crystals can be well explained directly from the types and spatial arrangements of B-O groups. The deduced mechanism understanding has significant implications for the exploration and design of new borate-based crystals with excellent UV and DUV NLO performance. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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9354 KiB

Open AccessReview

Borates—Crystal Structures of Prospective Nonlinear Optical Materials: High Anisotropy of the Thermal Expansion Caused by Anharmonic Atomic Vibrations

by Rimma Bubnova, Sergey Volkov, Barbara Albert and Stanislav Filatov

Crystals 2017, 7(3), 93; https://doi.org/10.3390/cryst7030093 - 22 Mar 2017

Cited by 47 | Viewed by 9601

Abstract

In the present study the thermal structure evolution is reviewed for known nonlinear optical borates such as β-BaB₂O₄, LiB₃O₅, CsLiB₆O₁₀, Li₂B₄O₇, K₂Al [...] Read more.

In the present study the thermal structure evolution is reviewed for known nonlinear optical borates such as β-BaB₂O₄, LiB₃O₅, CsLiB₆O₁₀, Li₂B₄O₇, K₂Al₂B₂O₇, and α-BiB₃O₆, based on single-crystal and powder X-ray diffraction data collected over wide temperature ranges. Temperature-dependent measurements of further borates are presented for the first time: α-BaB₂O₄ (295–673 K), β-BaB₂O₄ (98–693 K), LiB₃O₅ (98–650 K) and K₂Al₂B₂O₇ (98–348 K). In addition to the established criteria for nonlinear optical (NLO) properties of crystals, here the role of the anisotropy and anharmonicity of the thermal vibrations of atoms is analysed as well as changes in their coordination spheres and the anisotropy of the thermal expansion of the crystal structure. Non-centrosymmetric borates, especially those that have NLO properties, often show distinct anisotropies for each cation in comparison to centrosymmetric borates. All considered NLO borates contain BO₃ triangles, which are the principal cause of the strong anisotropy of the thermal expansion. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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734 KiB

Open AccessReview

On the Anionic Group Approximation to the Borate Nonlinear Optical Materials

by Rukang Li

Crystals 2017, 7(2), 50; https://doi.org/10.3390/cryst7020050 - 11 Feb 2017

Cited by 32 | Viewed by 4467

Abstract

In this mini-review type of article, a brief summary of the anionic group approximation as it relates to the borate nonlinear optical (NLO) crystals, an idea firstly proposed by Professor Chen, is presented.The basic idea, calculation method, tabulated coefficients of various common borate, [...] Read more.

In this mini-review type of article, a brief summary of the anionic group approximation as it relates to the borate nonlinear optical (NLO) crystals, an idea firstly proposed by Professor Chen, is presented.The basic idea, calculation method, tabulated coefficients of various common borate, as well as nitrate or carbonate groups, in their ideal geometries will be presented. New practices reveal that those parameters can still give very accurate predicted NLO coefficients for recently found NLO crystals without any adjustment of parameters. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals 2017—Commemorative Issue in Honor of Professor Chuangtian Chen on the Occasion of his 80th Anniversary)

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