Periodic Twinning in Crystal Quartz for Optical Quasi-Phase Matched Secondary Harmonic Conversion

Harada, Masaki; Muramatsu, Keiichiro; Iwasaki, Yutaka; Kurimura, Sunao; Taira, Takunori

doi:10.1557/jmr.2004.0125

Cited by 23 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, QPM devices result in an amplification of conversion light. Generally, QPM structures can be induced by the poling method − and the hot-pressing method. However, since borate crystals are paraelectric at 30 °C, it is difficult to control the appearance of twin boundaries in SBO utilizing the poling and hot-pressing methods.…”

Section: Introductionmentioning

confidence: 99%

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method

Inaba

Ishibashi

Asakawa

et al. 2020

Crystal Growth & Design

View full text Add to dashboard Cite

SrB 4 O 7 (SBO) has received much attention as a solid-state ultraviolet laser crystal for a wide variety of applications such as micromachining and spectroscopy. Here we demonstrate the effects of electric fields E on the growth of SBO crystals along the b axis by the μ-pulling-down method to fabricate SBO with periodic twins, which increases the conversion light intensity. During the growth, the direction of electric fields was alternated for 30 min periods. The crystal fibers were evaluated by polarized optical microscopy, X-ray diffraction, and transmission electron microscopy. Without an external voltage, single SBO crystals grew. In contrast, at E ≥ 400 V/cm needles of SrB 2 O 4 appeared inside SBO fibers. At E ≥ 1000 V/cm, new domains of SBO grew from the seed crystals, and interestingly, growth twins were formed perpendicular to growth fronts. Thus, we found that the growth of SBO by the μ-PD method via alternating the application of opposing electric fields exhibits two mechanisms. In contrast, when the electrodes in melt and growth fronts switched to + and −, respectively, growth fronts changed from concave into convex shapes, irrespective of E. We could explain the relation between the two mechanisms and the inversion of surface shapes, using the convection.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method

Inaba

Ishibashi

Asakawa

et al. 2020

Crystal Growth & Design

View full text Add to dashboard Cite

show abstract

“…8(a) indicates the c-axes of micro-domains in Nd:FAP ceramis are well-aligned along magnetic field. The degree of crystal orientation of the sample can be quantitatively evaluated from XRD patterns with the Lotgering factor f [27] (20) where I(hkl) and A are diffraction intensity of peak (hkl), and a set of peaks that are diffracted by the target plane of orientation alignment, respectively. If f equals to 0, microdomains in the evaluated sample have random crystal orientations.…”

Section: Alignment In Anisotropic Laser Ceramics 51 Fabrication Of Tmentioning

confidence: 99%

“…However, use of pressure sintering for aligning microdomains in laser ceramics is not suitable due to the induced residual stress to microstructures inside final products. Another possibility of this term for the orientation control is proved by the fabrication of the periodically domain inverted quartz [20].…”

mentioning

confidence: 99%

Fundamental investigations in orientation control process for anisotropic laser ceramics

Sato

Akiyama

Taira

2013

Phys. Status Solidi C

Self Cite

View full text Add to dashboard Cite

We present theoretical studies on the orientation control of micro‐domains in anisotropic laser ceramics. The direction of the crystal axis that is parallel to easy magnetization in each micro‐domain can be aligned along the direction of the applied magnetic field via two steps of fabrication processes. In the first step the alignment is performed during the slip‐casting under the magnetic field, where directions of primary particles are forced to align along the direction of easy magnetization. However, even though rare‐earth trivalent ions doped into primary particles as luminous ions enhance their magnetic moment, the perfect alignment control is not always possible due to Brownian fluctuations by slurry solvent at this stage. The further orientation control can be processed by the preferential grain growth, where an adequate orientation distribution of primary articles in the casted green body is required for the nearly perfect alignment in sintered ceramics. Therefore, it is important for further improvements of anisotropic laser ceramics to find the orientation distribution of primary particles in the slurry, which is determined by the ratio between the anisotropic magnetic potential and the thermal fluctuations. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

“…Hence, the conversion light is, generally, amplified owing to the QPM structure. It is well-known that QPM structures in ferroelectric oxide materials can be formed by the application of an external electric field such as the poling method [10,[12][13][14][15] and hot-pressing method [16]. However, since borates are non-ferroelectric crystals, with the utilization of the poling method and the hot-pressing method it is difficult to control twin boundary orientation.…”

Section: Introductionmentioning

confidence: 99%

Growth of SrB4O7 Crystal Fibers along the c-Axis by Micro-Pulling-Down Method

2021

View full text Add to dashboard Cite

SrB4O7 (SBO) receives much attention as solid-state ultraviolet lasers for micro-machining, photochemical synthesis, and laser spectroscopy. For the application of SBO, the SBO crystals require the control of twinning to amplify the conversion light. We also expected that the inhibitation of the SrB2O4 appearance was essential. Here, we show the growth of SBO crystals along the c-axis through the micro-pulling-down method while alternating the application of electric fields (E). Without the application, single crystals were grown. At E ≧ 400 V/cm no needle domains of SrB2O4 inside SBO crystals existed; however, composition planes were formed and twin boundaries did not appear. In contrast, the inversion of surface morphology emerged, and the convex size was especially large at 1000 V/cm. These results demonstrate that convection is generated perpendicular to the growth front by alternating the application of electric fields. This surface morphological change contradicts the conventional concept of growth through the micro-pulling-down method. The distance from seed crystals vs. grain density plot also showed that the density did not decrease with a sufficient slope. Consequently, we concluded that the selection of the c-axis as growth faces is not fruitful to fabricate twins, and the selection of the growth condition, under which geometrical selection strongly affects, is the key.

show abstract

Periodic Twinning in Crystal Quartz for Optical Quasi-Phase Matched Secondary Harmonic Conversion

Cited by 23 publications

References 3 publications

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method

Fundamental investigations in orientation control process for anisotropic laser ceramics

Growth of SrB4O7 Crystal Fibers along the c-Axis by Micro-Pulling-Down Method

Contact Info

Product

Resources

About

Periodic Twinning in Crystal Quartz for Optical Quasi-Phase Matched Secondary Harmonic Conversion

Cited by 23 publications

References 3 publications

Effects of the Application of Electric Fields on the Growth of SrB4O7 Crystals by the Micro-Pulling-Down Method

Effects of the Application of Electric Fields on the Growth of SrB4O7 Crystals by the Micro-Pulling-Down Method

Fundamental investigations in orientation control process for anisotropic laser ceramics

Growth of SrB4O7 Crystal Fibers along the c-Axis by Micro-Pulling-Down Method

Contact Info

Product

Resources

About

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method

Effects of the Application of Electric Fields on the Growth of SrB₄O₇ Crystals by the Micro-Pulling-Down Method