• Proceedings of the Korean Society of Laser Processing Conference
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• 2003.05a
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• pp.122-126
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• 2003

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.05a
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• pp.54-55
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• 1998

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.11a
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• pp.20-23
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• 1998

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.226-232
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• 1999

We have investigated the output power performance of a continuous-wave chromium-doped YAG laser ($Cr^{4+}$:YAG laser), pumped by a Nd: YAG laser. With an output coupler of 1% transmission, we obtained as much as 400 mW of the average output power at 1.450 ${\mu}{\textrm}{m}$. The power slope efficiency of 8%, when the gain medium was cooled to 2$0^{\circ}C$. We tuned the wavelength of the $Cr^{4+}$:YAG laser, at pump power of 6 W, by using birefringent filter. As a result, lasing wavelength was tuned from 1.399 ${\mu}{\textrm}{m}$ to 1.532 ${\mu}{\textrm}{m}$, with the maximum output power of 340 mW at 1.4903 ${\mu}{\textrm}{m}$ and the linewidth was 0.21 nm.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2003.05a
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• pp.35-38
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• 2003

• Proceedings of the Optical Society of Korea Conference
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• 1988.06a
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• pp.1-8
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• 1988

상용 가공용 Nd:YAG 레이저의 특성 및 제원 을 분석하고 설계 시 고려하여야 할 thermal lensing 효과의 영향에 따른 출력특성의 제한에 대하여 기술하였으며 이를 토대로 200W급의 Nd:YAG 레이저를 설계하였다.

• Journal of Welding and Joining
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• v.9 no.1
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• pp.32-39
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• 1991

A 200W pulsed Nd: YAG laser for fine welding was developed. The important laser parameters such as laser peak power, average power, pulse width, and pulse energy for welding were studied. In order to obtain the sufficient laser power density for welding, thermal lensing effects were analyzed and a laser resonator with laser beam divergence was designed. The power supply unit was designed to support up to 7kW input. The pulse control unit was developed using a GTO thyristor and could control over 100kW input power to obtain 3.5kW peak power laser. Also due to the GTO thyristor the pulse width could be varied continuously from 0.1 to 20 msec and maximum repetition rate was as high as 300pps.

• Laser Solutions
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• v.4 no.2
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• pp.47-57
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• 2001

This study deals with the laser cutting of stencil for the PCB. The most important aim of this study is to determine optimal conditions which make good-qualify stencil in Nd:YAG laser cutting. We made an experiment according to various variables (power. type of mask. gas pressure, cutting speed, and pulse width) and analyzed the cutting characteristics (surface roughness, kerf width. dross) . Each variable has optimal value for good-qualify cut edge under fixed condition. And neural network after learning experimental data with a million time iteration could predict surface roughness of cut edge under arbitrary condition approximately.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.456-461
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• 2005

We numerically investigate the characteristic of single Nd:YAG rod laser with the convex-plane resonator configuration in order to get the best condition for high efficient intra-cavity second harmonic generation(SHG). The beam quality is analyzed with ABCD matrixes including the thermal lensing characteristic of Nd:YAG rod. The analysis is focused on stability, M2, beam waist and mode-volume of laser beam inside the resonator. The best conditions for SHG is obtained when a laser rod is set near the curved laser mirror.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.130-131
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• 2003

수술용으로 쓰이는 치과용 레이저로는 Nd：YAG, $CO_2$, Er：YAG 레이저들이 있다. 치료 부위에 따라 두 가지 응용으로 나눌 수 있다. 잇몸의 절개 등은 주로 $CO_2$나 Nd：YAG 레이저를 이용하여 정밀하게 그리고 출혈을 최소로 하는 레이저의 장점을 살리면서 시술하고 있다. $CO_2$레이저의 경우 강한 열적 손상작용 때문에 출력 조사 시간을 짧게 하여 사용하며, 열적 손상력이 낮은 Nd：YAG 레이저는 화이버를 접촉식으로 하여 화이버의 작은 면적의 높은 광밀도를 이용하여 시술하고 있다. (중략)