• Medical Lasers
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• v.9 no.2
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• pp.110-118
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• 2020

The non-ablative fractional dual laser is equipped with two types of lasers, 1550 nm and 1927 nm in one device, and was approved by the United States Food and Drug Administration in 2013. The advantages of the non-ablative fractional laser (NAFL) include fewer side effects such as erythema, edema, post-laser pigmentation, and scab formation. Thus, the NAFL is preferred by both practitioners and consumers because it is convenient and safe for use. The 1550 nm erbium glass and 1927 nm thulium lasers are representative NAFLs that have been developed separately and are often used as a single-wavelength laser with proven clinical efficacy in various indications. The 1550 nm wavelength laser penetrates the dermis layer and the 1927 nm wavelength laser is effective for epidermal lesions. Therefore, targeting the skin layer can be easily achieved with both the 1550 and 1927 nm lasers, respectively, or in combination. Clinically, the 1550 nm laser is effective in the treatment of mild to moderate sagging and wrinkles, scars, and resurfacing. The 1927 nm laser improves skin texture and treats skin pigmentation and wounds. It can also be used for drug delivery. The selection and utilization rate of NAFL has been increasing in recent times, due to changes in lifestyle patterns and the need for beauty treatments with fewer side effects and short downtime. In this study, we present a plan for safe and effective laser therapy through a review of literature. Clinical applications of the multifunctional NAFL are also described.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.12-24
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• 2023

With the improvement of laser technology, the strategic needs of efficient and precise decontamination of various components in nuclear application units can be fulfilled by laser decontamination. The surface contaminants of nuclear facilities mainly exist both as loose contaminated layer and fixed oxide layer. The types of radionuclides and contamination layer thickness are closely related to the operation status of nuclear facilities, which have an important influence on the laser decontamination process. This study reviewed the mechanism of laser surface treatment and the influence of laser process parameters on the decontamination thickness, decontamination factor, decontamination efficiency and the distribution of aerosol particle. Although multiple studies have been performed on the mechanism of laser processing and laser decontamination process, there are few studies on the microscopic process mechanism of laser decontamination and the influence of laser decontamination on surface properties. In particular, the interaction between laser and radioactive contaminants needs more research in the future.

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.40-40
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• 2010

• Medical Lasers
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• v.9 no.2
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• pp.142-149
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• 2020

Background and Objectives A picosecond-domain laser treatment using a microlens array (MLA) or a diffractive optical element elicits therapeutic micro-injury zones in the skin. This study examined the patterns of tissue reactions after delivering multiple pulses of 1,064-nm, MLA-type, picosecond neodymium:yttrium-aluminum-garnet laser treatment. Materials and Methods Multiple pulses of picosecond laser treatment were delivered to ex vivo human or brown micropig skin and analyzed histopathologically. A high-speed cinematographic study was performed to visualize the multiple pulses of picosecond laser energy-induced skin reactions in in vivo human skin. Results In the ex vivo human skin, a picosecond laser treatment at a fluence of 0.3 J/cm² over 100 non-stacking passes generated multiple lesions of thermally-initiated laser-induced optical breakdown (TI-LIOB) in the epidermis and dermis. In the ex vivo micropig skin, stacking pulses of 20, 40, 60, 80, and 100 at a fluence of 0.3 J/cm² generated distinct round to oval zones of tissue coagulation in the mid to lower dermis. High-speed cinematography captured various patterns of twinkling, micro-spot reactions on the skin surface over 100 stacked pulses of a picosecond laser treatment. Conclusion Multiple pulses of 1,064-nm, MLA-type, picosecond laser treatment elicit marked TI-LIOB reactions in the epidermis and areas of round to oval thermal coagulation in the mid to deep dermis.

• Medical Lasers
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• v.8 no.1
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• pp.1-6
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• 2019

Background and Objectives A facial laceration is a commonly occurring trauma of children. In addition, appropriate treatment and scar management are very important because the psychosocial impact of facial scars is much greater in children than in adults. Materials and Methods In the authors' hospital, primary closure was conducted targeting a total of 8,924 patients from January 2015 to December 2017. Of these, scar management was conducted on 808 people using a CO₂ fractional laser and Q-Switch Nd:YAG laser. To prove the effectiveness of the laser treatment on the linear scar, the patients were divided retrospectively into children and adults and sub-divided into those who received the treatment and those who did not. The subjective satisfaction of patients was evaluated using the Numeric Rating System (NRS). The objective scar scoring was evaluated using the image panel assessment based on the Vancouver Scar Scale (VSS), and the scoring was made by averaging the evaluations of three plastic surgeons. Results Evaluated NRS showed 8.50 ± 1.83 for adults without a laser, 8.51 ± 1.47 for adults with a laser, 7.93 ± 2.10 for children without a laser, and 8.9 ± 1.24 for children with a laser. The image panel assessment revealed 7.06 ± 1.31 for adults without a laser, 6.40 ± 2.37 for adults with a laser, 6.86 ± 1.45 for children without a laser, and 5.93 ± 1.21 for children with a laser. Conclusion When the linear scar is managed using a CO₂ Fractional laser, it can be managed in children better than adults, which is believed to be useful because it leads to better satisfaction and prognosis.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.667-671
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• 1989

The CO laser is one of powerful light source for laser magnetic resonance spectroscopy in the mid-infrared region of the spectrum because of its wideband operational characteristics. In this work, a liquid nitrogen cooled cw CO laser is developed to allow broad-band operation from 5 to 8 ${\mu}m$. The design details will be presented.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.50-55
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• 1991

Mg 원자선속의 냉각에 쓰일 diode laser의 특성과 이용가능성을 연구하였다. Mg 원자의 3P2-3D3 천이의 공명선 383.8nm를 얻기 위하여 Mitsubishi사의 ML형 laser diode를 택하여 주입전류와 온도를 변화시키고, 회절격자를 써서 767.6nm의 laser 광을 얻은 후 LiIO3 결정에 의해 383.8nm인 제2조화파를 생성하였다. Ring cavity 내에서 기본파가 공명할 때 증강계수는 15이었다.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.95-96
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• 2004

그동안 고출력 레이저에는 CO2 Laser, LPSSL, DPSSL 등이 주로 사용되어 왔다. 최근에는 Fiber Laser가 좋은 빔특성을 가지면서 10㎾이상의 고출력이 가능해 큰 주목을 받고 있다. 고출력 레이저는 매질의 냉각문제가 가장 큰 관건인데, Fiber Laser는 수백 $\mu\textrm{m}$의 지름을 가진 수십m 길이의 공진기 형태를 띠어 부피 대비 냉각면적이 가장 크다고 할 수 있다. EDFA 등 광통신을 위해 개발되었던 다이오드 레이저들이 Fiber Laser쪽으로 전용되고, Side Cladding pumping 방법의 실용화, 다이오드 페이저 펌핑 광과 광섬유사이의 커플링 방법이 개발되면서 고출력 Fiber Laser 개발이 급속히 이루어졌다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.160-163
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• 2002

Micro via hole Fabrication is studied by means of minimizing method to circuit size as many electric products developed to portable and minimize. Most of currently micro via hole fabrication using laser is that fabricate insulator layer using CO2 Laser after Cu layer by etching, or fabricate insulator layer using IR after trepanning Cu by UV. In this paper, it was performed that a metal layer and insulator layer were worked upon only one UV laser, and increase to processing speed by experiment.

• Laser Solutions
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• v.4 no.2
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• pp.39-45
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• 2001

This paper introduces a cleaning process for removing submicron-sized particles from NiP hard disk substrates by the liquid-assisted laser cleaning technique. Measurements of cleaning Performance and time-resolved optical diagnostics are Performed to analyze the physical mechanism of contaminant removal. The results reveal that nanosecond laser pulses are effective for removing the contaminants regardless of the wavelength and that a thermal mechanism involving explosive vaporization of liquid dominates the cleaning process.