• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.06a
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• pp.3-5
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• 1998

The interest in the use of borate crystals in ultraviolet(UV) nonlinear optics(NLO) has increased because all solid-stste UV lasers obtained with NLO are in highly demand. Much effort has been spent on developing borates series, such as{{{{ { beta -BaB }_{2 } {O }_{4 }(BBO), {LiB }_{ 3}{O }_{5 }(LBO)}}}} and{{{{{ CsKiB}_{6 }{O }_{10 }(CLBO)}}}} in this decade. Recently another new borate crystals, {{{{{ YCa}_{4 }O({BO }_{3 })_{3}}}}} and{{{{{Gd }_{x }{Y }_{1-x }{Ca }_{4 }O({BO }_{ 3})({Gd }_{x }{Y }_{1-x }COB)}}}} have been developed by the present authors. Here, the growth and NLO properties of YCOB and {{{{ {Gd }_{ x} {Y }_{ 1-x} }}}}CO B crystal are reported and their properties discussed in relation to those of other nonlinear optical crystals, such as LBO.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.91-96
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• 1998

An empirical relationship which can be calculated to the lattice constants $a_0$ and $c_0$ for the borate crystals with huntite structure were determined. Different compositions of twenty-eight were used for the calculations. These empirical formulas can be used to predict lattice parameters of unknown compositions as a function of the average ionic radii in the trigonal and octahedral sites of the huntite structure.

• Current Optics and Photonics
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• v.5 no.4
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• pp.458-465
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• 2021

Borate nonlinear optical crystals have been used as frequency conversion devices in many fields due to their unique transparency and nonlinearity from ultraviolet to visible spectral range. In this study, we theoretically and numerically investigate the properties of broadband second harmonic generation (SHG) in the recently reported Pna2₁-Ba₃Mg₃(BO₃)₃F₃ (BMBF) crystal. The technique is based on the simultaneous achievement of birefringence phase matching and group velocity matching between interacting waves. We discussed all factors required for broadband SHG in the BMBF in terms of two types of phase matching and group velocity matching conditions, the beam propagation direction and the corresponding effective nonlinearity and spatial walk-off, and the spectral responses. The results show that bandwidths calculated in the broadband SHG scheme are 220.90 nm (for Type I) and 165.85 nm (for Type II) in full-width-half-maximum (FWHM). The central wavelength in each case is 2047.76 nm for Type I and 1828.66 nm for Type II at room temperature. The results were compared with the non-broadband scheme at the telecom C-band.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.5
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• pp.459-462
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• 1999

Recent advances in NLO Borate Crystals for UV Generation are reviewed with the particular emphasis on the technique to improve the life time of UV optics. The laser-damage resistance of CLBO and fused silica surfaces was successfully improved after removing polishing compound by ion beam etching. The polishing compound embedded in the CLBO and fused silica surfaces were to a depth of less than 100nm. We were able to remove polishing compound without degrading the surface condition when the applied ion beam voltage was less than 200 V. The laser-induced surface damage threshold of CLBO was improved up to 15J/$\textrm{cm}^2$(wavelength: 355 nm, pulse width: 0.85 ns)as compared with that of the as-polished surface (11 J/$\textrm{cm}^2$). The laser-induced surface damage of fused silica also increased from 7.5J/$\textrm{cm}^2$ to 15J/$\textrm{cm}^2$. For the irradiation of a 266 nm high-intensity and high-repetition laser light, the surface lifetime of CLBO and fused silica could be more doubled compared with that of the as-polished surface.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.68-68
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• 2000

In this paper a very brief review of historical development of optical science and technology in China is presented. More attention has been pain on Modem Optics, which developed since 1950s. The recent development of optical science and technology in following fields are introduced. 1. Optical engineering and instrumentation (tracking theodolites, high speed cameras, satellite laser ranging systems, satellite flying attitude control, cameras for remote sensing, astronomical optical instrument) 2. Applied optics (adaptive optics, optical metrology, infrared optics, optical processing, optical holography) 3. Laser science and technology (ultrashort pulse lasers, UV-X ray lasers, high power laser facilities and laser fusion, laser isotope separation) 4. Laser and nonlinear materials (rare earth elements doped laser glasses and crystals, tunable laser crystals, borate series and organic nonlinear crystals) 5. Optoelectronic science and technology (Optical communication, optical data storage, optical computing) The current situation and developing prospect of optical and optoelectronic industry in China are presented. Furthermore it points out that the optical industry could be developed vigorously only if products development capacity is enhanced and new products industrialization is heightened. The main research and education institutions in the optics field in China, as well as the Chinese Optical Society (COS) are introduced.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.244-245
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• 2000

비선형광학 결정을 이용한 optical parametric generation(OPG)은 coherent tunable radiation을 얻는 방법으로 매우 효과적이다. Beta barium borate(BBO) 결정은 비선형성이 클 뿐만 아니라 광손상문턱이 높고 자외선에서부터 근 적외선영역까지(2 -0.2$mu extrm{m}$) 투명하여 optical parametric oscillation(OPO)이나 OPG/OPA(optical parametric generation/amplification)에 많이 활용되고 있다.[1-2] 분광학적 연구와 여러 가지 응용 측면에서 넓은 영역의 파장가변이 손쉽고 높은 에너지를 갖는 pico 초coherent source는 중요하며, 이는 결정의 비선형성을 이용하여 공진기를 구성하지 않고서도 OPG/OPA를 통하여 실현 가능하다. (중략)

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.15-20
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• 1998

Single crystals of lithium heptaborate, Li3B7O12(M=288.49), have been grown and their structure was determined by the x-ray powder diffraction and the single crystal diffraction technique. It is found that the borate anion consists of two(B3O7)3- and (B3O8)5- groups a unit cell. The space group was determined to be P-1(Ci1) with a=6.500(3) Å, b=7.839(2) Å, c=8.512(1) Å, α=92.07(2)˚, β=104.97(2)˚, γ=99.35(3)˚, V=412.0(2) Å3, Z=2 Dx=2.32 g cm-3, MoKα, λ=0.71069 Å, μ=2.15cm-1, T=293K. The structure was refined to R=0.0339 and wR=0.0882 for 2296 unique reflections by the single crystal diffraction. By the x-ray powder diffraction, we could obtain the similar results.