• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.246-247
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• 2000

Yb$^{3+}$ 이온은 InGaAs LD 및 Ti:sapphire 레이저로 펌핑할 수 있는 940 nm에서의 흡수대를 가지고 있고, 1.03 $mu extrm{m}$의 형광방출 특성을 가지고 있으며, 지금까지 알려진 1 $\mu\textrm{m}$ 파장대의 레이저 활성이온 중에서 가장 적게 열을 발생하는 특성을 가지고 있음이 알려져 최근에는 Yb$^{3+}$ 이온을 첨가한 여러 가지 레이저 매질이 연구되고 있다.[1] 그 중에서도 Yb$^{3+}$ ion doped yttrium aluminum garnet (Yb:YAG) 단결정은 충분하게 넓은 흡수선폭, 좋은 열광학적 특성, 고출력 작동을 하게 하는 stokes shift, 그리고 LD에 의한 펌핑을 가능하게 하는 940 nm 영역에서의 흡수 및 긴 여기시간을 가진 이상적인 매질로 알려져 있다.[2] 이러한 특성으로 인해 Yb:YAG 단결정은 femtosecond 레이저 등 각종 레이저 시스템의 소형화[3]를 가져왔으며, 레이저 결정의 양산 가능성 및 레이저 기기의 소형화에 따르는 시스템의 가격 감소가 가능하므로 Yb:YAG microchip 레이저는 향후 고출력 레이저 기기 산업의 중추가 될 것으로 기대된다. (중략)

• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.911-916
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• 1998

By using {{{{ { { {Y }_{3 }Al }_{5 }O }_{12 } }} (YAG) and SiO2 as sintering additives the effect of the composition of sintering ad-ditives on microstructure and mechanical properties of the hog-pressed and subsequently annealed SiC ma-terials were investigated. Microstructures of sintered and annealed materials were strongly dependent onthe composition of sintering additives. The average diameter and volume fraction of elongated grains in an-nealed materials increased with the SiO2/YAg ratio while the fracture toughness increased with the SiO2/YAg ratio. The average MPa.{{{{ { m}^{1/2 } }} respectively. Typical strength and fracture toughness of an annealed material with SiO2/YAg ra-tionof 0.67 were 371 MPa and 5.6 MPa.{{{{ { m}^{1/2 } }} respectively.

• Medical Lasers
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• v.8 no.1
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• pp.32-34
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• 2019

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis of the skin that occurs as a result of variable inflammatory processes, such as trauma, and many inflammatory conditions. Although a range of modalities of managing PIH have been reported, the treatment of PIH is challenging. In this report, a patient with PIH was treated using picosecond-domain Nd:YAG lasers. After three sessions of 1,064-nm picosecond-domain Nd:YAG laser treatment, the patient showed almost complete improvement with no remarkable side effects or recurrence over the duration of six months. Overall, 1,064-nm picosecond-domain Nd:YAG laser can be used effectively and safely for treating pigmented lesions in the dermis, particularly PIH, in Asian patients.

• Korean Journal of Materials Research
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• v.30 no.11
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• pp.573-580
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• 2020

YAG (Yttrium Aluminum Garnet, Y₃Al₅O₁₂) has excellent plasma resistance and recently has been used as an alternative to Y₂O₃ as a chamber coating material in the semiconductor process. However, due to the presence of an impurity phase and difficulties in synthesis and densification, many studies on YAG are being conducted. In this study, YAG powder is synthesized by an organic-inorganic complex solution synthesis method using PVA polymer. The PVA solution is added to the sol in which the metal nitrate salts are dissolved, and the precursor is calcined into a porous and soft YAG powder. By controlling the molecular weight and the amount of PVA polymer, the effect on the particle size and particle shape of the synthesized YAG powder is evaluated. The sintering behavior of the YAG powder compact according to PVA type and grinding time is studied through an examination of its microstructure. Single phase YAG is synthesized at relatively low temperature of 1,000 ℃ and can be pulverized to sub-micron size by ball milling. In addition, sintered YAG with a relative density of about 98 % is obtained by sintering at 1,650 ℃.

• Archives of Plastic Surgery
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• v.42 no.1
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• pp.52-58
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• 2015

Background The erbium:yttrium scandium gallium garnet (Er:YSGG) laser differs from other laser techniques by having a faster and higher cure rate. Since the Er:YSGG laser causes an appropriate proportion of ablation and coagulation, it has advantages over the conventional carbon dioxide ($CO_2$) laser and the erbium-doped yttrium aluminum garnet (Er:YAG) laser, including heating tendencies and explosive vaporization. This research was conducted to explore the effects and safety of the Er:YSGG laser. Methods Twenty patients participated in the pilot study of a resurfacing system using a 2,790-nm Er:YSGG laser. All patients received facial treatment by the 2,790-nm Er:YSGG laser system (Cutera) twice with a 4-week interval. Wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture were measured. Results Study subjects included 15 women and five men. Re-epithelization occurred in all subjects 3 to 4 days after treatment, and wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture within 6 months of treatment. Conclusions The 2,790-nm YSGG laser technique had fewer complications and was effective in the improvement of scars, pores, wrinkles, and skin tone and color with one or two treatments. We expect this method to be effective for people with acne scars, pore scars, deep wrinkles, and uneven skin texture and color.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.440-441
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• 2007

For this study, terbium-doped yttrium aluminum garnet (YAG:Tb) phosphor powders were prepared via the combustion process using the varous reagents. The characteristics of the synthesized nano powder were investigated by means of X-ray diffraction (XRD), Scanning Electron Microscope(SEM), and photoluminescence (PL). Single-phase cubic YAG:Tb crystalline powder was obtained at $1000^{\circ}C$ by directly crystallizing it from amorphous materials, as determined by XRD techniques. The SEM image showed that the resulting YAG:Tb powders had uniform sizes and good homogeneity. The photoluminescence spectra of the YAG:Tb nanoparticles were investigated to determinethe energy level of electron transition related to luminescence processes. There were three peaks in the excited spectrum, and the major one was a broad band of around 274 nm. Also, the YAG:Tb nanoparticles showed two emission peaks in the range of 450~500 nm and 525~560 nm, respectively, and had maximum intensity at 545 nm.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.657-659
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• 2004

Trivalent cerium ($Ce^{3+}$) activated yttrium aluminum garnet ($Y_3Al_5O_{12}$, YAG) phosphor thin films were deposited on quartz glass substrates by rf magnetron sputtering. The effects of sputtering parameters and annealing condition on the luminescent properties were investigated. The sputtering parameters were $O_2$/Ar gas ratio, rf power, and deposition time. The films were annealed at 1200 $^{\circ}C$ for 5 hours in $N_2+$vacuum atmosphere. Polycrystalline YAG:Ce thin film phosphor could be obtained with a gas ratio of $O_2$/(Ar+$O_2$)=0.5 after post-annealing. PL spectra excited at 450 nm showed a yellow single band at 550 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.406-407
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• 2008

For this study, Yttrium aluminum garnet (YAG) particles doped $Eu^{3+}$ ions were prepared via the combustion process using the 1:1 ratio of metal ions to reagents. The characteristics of the synthesized nano powder were investigated by means of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and photoluminescence (PL). The various YAG peaks, with the (420) main peak, appeared at all sintering temperature XRD patterns. The YAG phase crystallized with results that are in good agreement with the JCPDS diffraction file 33-0040. The SEM image showed that the resulting YAG:Eu powders had larger sizes with the increse in the sintering temperature. The grain size was about 50nm at $1000^{\circ}C$. The PL intensity of $Eu^{3+}$ has the line peaks of 598, 610, 632nm and has main peak at 591nm.

• Korean Journal of Materials Research
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• v.15 no.8
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• pp.548-553
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• 2005

Trivalent cerium$(Ce^{3+})$ activated YAG (yttrium aluminum garnet, $Y_3Al_5O_{12})$) thin films phosphor were deposited on quartz glass substrates by rf magnetron sputtering. The effects of sputtering parameters, annealing atmosphere, and substrates on growing behaviors and luminescent properties were investigated. The sputtering parameters were $O_2/(Ar+O_2)$ gas ratio, rf power, and deposition time. XRD (X-ray diffractometery) spectra exhibited that as-deposited films were amorphous, while they were transformed to the crystalline phases by post-annealing. The crystallinity and the atomic ratio strongly depended on the sputtering gas ratio $O_2/(Ar+O_2)$. High quality YAG:Ce thin films could be obtained at the gas ratio of $50\%$ oxygen. After annealing process, PL (Photoluminescence) spectra excited at 450nm showed a yellow single band at 550nm. The films deposited at the sputtering gas ratio of 50% oxygen exhibited the highest PL intensity.

• Journal of the Korean Ceramic Society
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• v.44 no.5 s.300
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• pp.151-154
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• 2007

Yttrium aluminum garnet, $Y_3Al_5O_{12}$ (YAG) is an extensively used solid-state laser host material. YAG nanocrystals were synthesized using low-temperature glycol method, a modified sol-gel method performed at low temperature that consists of a mixture of salts that are mostly nitrates in an aqueous media. Single-phase nanocrystalline YAG was obtained at $850^{\circ}C$, which is a much lower temperature than with other techniques such as a wet-chemical technique. The structural characterization is done by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. A crystallite size range of 20-50 nm was observed for the materials prepared at $850-950^{\circ}C$.