• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.100-100
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• 1997

• Journal of Welding and Joining
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• v.22 no.1
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• pp.32-37
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• 2004

• Proceedings of the Korean Society of Laser Processing Conference
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• 2000.06a
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• pp.3-6
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• 2000

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.157-161
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• 2004

This study proposed the possibility of the medical cure by thermal feedback as the laser medical treatment had given and by the development of digital I/O interfaces of the electronic shutter to control the laser beam and of the temperature controlled algorithm. The development of the electronic shutter driving such interfaces and its controlled algorithm was designed to be automatically controlled within the range of an extent temperture.

• Journal of the Korean Vacuum Society
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• v.3 no.3
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• pp.280-285
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• 1994

본 연구에서는 Al 금속 표면에 CW CO2 레이저 빔의 조사시 표면 온도의 증가에 따른 표면과 기체 분자의 계면사이에서 발생하는 다양한 물리적 현상을 측정하였다. 온도 증가에 따른 계면에서의 물리적 현상은 Al 표면에 힘의 변화를 초래하는데 이 힘의 변화를 시간에 따라 정확학게 측정하고 측정 한 힘을 온도와 연계하여 분석하면 계면의 상호작용에 의한 물리적 현상을 설명할 수 있다. 즉 레이저 와 표면의 상호 작용은 레이저 강도에 따라 기체와 표면사이의 에너지 및 선운동량의 전달, 표면 흡착 원자의 방출 및 표면물질의 증발 등으로 구분되는데, 이러한 상호 작용시 수반되는 힘의 변화를 이용하 여 Al 금속 표면에 대한 기체 종류별 Momentum Accommodation Coefficient (MAC)를 계산하였고, Al 표에 흡착된 원자의 종류,갯수 및 결합에너지를 구하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.567-574
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• 2007

Aluminum and aluminum alloys have high rate of lightness, recycling property and excellent specific strength. Fields using them have been widening because they ould satisfy both energy reduction and high efficiency in manufactures production. But they have many problems on welding due to high thermal conductivity and reflectivity, so the study to solve these problems ate proceeding actively around the world. This study was purposed to improve weldability and spread application range for aluminium alloys by using the unique property of aluminium which absorb high energy around $800{\mu}m$ wavelength and the higher temperature, the mote absorbtion of laser beam on preheating by multi-wavelength laser beam(pulsed Nd:YAG laser + diode laser with $808{\mu}m$ wavelength). The favorable mechanical properties were acquired by the test results of strength, hardness and leak of weld metal which had reduced its defect like crack and so on.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.9-12
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• 2004

A numerical simulation is presented for investigating the effects of pressure ratio of $D_2$ injector to supersonic nozzle on the Population inversion in the DF chemical laser cavity, while a latins concurrently takes place. In this study, these phenomena are investigated by means of analyzing the distributions of the DF excited molecules, while simultaneously estimating the maximum small signal gains and power in the DF chemical laser cavity. Major results reveal that the higher $D_2$ injection pressure provides a favorable condition for $DF^{(1)}$-$DF^{(0)}$ transition to generate the higher power laser beam.

• Korean Journal of Optics and Photonics
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• v.35 no.4
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• pp.157-163
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• 2024

We developed a 3-channel fiber laser with a common seed and a phase control system for laser beam combining through a diffractive optical element. Beam combining was performed by adjusting the angles of the beams incident on the diffractive optical elements, and the phase of each beam was controlled to maximize the intensity of the combined laser beam. The power of the 3-channel laser before passing through the diffractive optical elements is about 65 mW. The power of the combined beam varied between 2.9 mW and 48.3 mW depending on the phase change of each channel. Through phase control, the output of the combined beam can be maintained at 42 mW for more than 91.8% of the total time. It is expected that higher combining efficiency can be achieved by improving the transmittance of the diffractive optical elements and the performance of the phase control system.

• Defense and Technology
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• no.11 s.141
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• pp.68-73
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• 1990

군사용으로 레이저가 쓰일 곳은 대단히 많다. 예를들어 프랑스와 미국은 가스나 증기를 탐지해내는 레이저 장비를 개발한 적이 있다. 다른 응용으로 항공기의 계기판이 있다. 조종사들이 계기들에 의존하여 비행하는 경우 인공지평선을 기준으로 삼고 있으나, 이것을 시야에서 놓치는 경우 방향감각을 상실할 가능성도 있다. 이의 해결책으로서 레이저가 밝은 적색 빔으로 전체 계기판을 비추어 인공 지평선을 만들어주는 방법이 개발되었다. 이는 미국 Allied Signal Aerospace사에서 개발하였다

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.05a
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• pp.29-30
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• 1998