• Journal of Welding and Joining
• /
• v.22 no.2
• /
• pp.23-27
• /
• 2004

최근 레이저-아크 하이브리드용접에 대한 연구가 활발히 진행되고 있다. 이미 고출력 $CO_2$ 레이저가 보편화되면서 레이저용접이 차체제작에 널리 사용되고 있으며 고출력 Nd:YAG 레이저의 출현으로 알루미늄 레이저용접의 적용 가능성이 크게 증가하였을 뿐만 아니라 광화이버를 통하여 빔을 전달할 수 있어 좀 더 복잡하고 입체적인 물체를 용접할 수 있는 로봇 레이저 용접을 구현할 수 있게 되었다.(중략)

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2009.04a
• /
• pp.41-48
• /
• 2009

Laser diode is used as a crucial part for minimization of terrestrial 3D Laser Scanner. But it has certain limitations such as oval beam shape and inevitable astigmatism. In order to realize a parallel light with beam divergence below 1 mrad, These problems of laser diode can be solved through beam shaping by Pinhole and Aperture. Finally, this study could materialize a collimated beam with 0.3 mrad beam divergence angle and 3mm diameter, that performance and checked by using real manufacture.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.4 s.36
• /
• pp.87-92
• /
• 2005

This study showed the possibility of the medical treatment by thermal feedback as the laser medical treatment had given by design of the digital I/O interfaces of the electronic shutter to control the laser beam and the temperature controlled algorithm. The electronic shutter is economical and that is designed to be automatically controlled within the range of an extent temperature by such development of its driving interfaces and the controlled algorithm of the electronic shutter. The possibility of local therapy for the patients by the treatment of the laser beam within an extent temperature controlled, is proposed by improvement of the problems on the current treatment methods such as radiotherapy, high frequency treatment or medical therapy of drug stuffs which even kill the normal cells.

• Journal of Welding and Joining
• /
• v.9 no.2
• /
• pp.29-36
• /
• 1991

6mm 두께의 AISI 316 스테인레스강의 레이저 용접 특성에 대해서 고찰하였다. 3kW C $O_{2}$레이저를 사용하였으며, 레이저 빔은 TE $M_{00}$모우드였고 연속파이었다. 용입 깊이, 비드 폭, 고온 크랙, 가공등의 특성을 고찰하는데 있어서, 레이저 출력은 1kW에서 2.5kW까지, 용접 속도는 5.1m/min까지 적용하였다. 3차원 열전달 방정식에 의한 용입 깊이와 비드 폭에 대한 예측치와 실험 결과를 비교하였는데, 서로 잘 일치하였다.다.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.5
• /
• pp.60-65
• /
• 1997

This paper proposes a profilometry system for precise surface contouring of 3D objects using a direc- tionally magnified image of a laser light stripe. The resolution of this system can be improved several times comparad with that of conventional systems without loss of spatial resolution and depth of measurement. A pair of cylindrical lens(a convex lens and a concave lens) are used for a directionally magnified image of a laser light stripe maintaining the same focal plane. Also, image processing procedures for image reconstruc- tions are described.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.177-183
• /
• 2005

In this work, Inconel 600, Inconel 625 and Haynes 230 are welding using Nd:YAG laser and electron bear. These heat-resistant alloys are typically used for the liquid thruster. To examine, the affects of experimental parameters on weld ability, the plate welding of these materials were carried out using both Nd:YAG laser and electron bear. Also, the micro-structure, micro-hardness, and tensile strength of the specimens were analyzed. from the analysis of the experimental results of laser and electron beam welding, we have obtained the optimal welding conditions.

• Korean Journal of Optics and Photonics
• /
• v.31 no.3
• /
• pp.142-147
• /
• 2020

In this paper, we report highly efficient second harmonic generation of continuous-wave Yb fiber lasers incorporating a periodically poled LiTaO₃ device (MgO:PPSLT) as a frequency converter. The seed laser output from a Yb fiber master oscillator using a Fabry-Perot feedback cavity was amplified in a Yb fiber amplifier stage, yielding 28.5 W of linearly polarized output at 1064 nm in a beam with beam quality, M², of ~1.07. Second harmonic generation was achieved by passing the laser beam through MgO:PPSLT. Under optimized conditions, we obtained 11.1 W of green laser output at 532 nm for an incident signal power of 25.0 W at 1064 nm, corresponding to a conversion efficiency of 44.4%. The detailed investigation to find the optimized operating conditions and prospects for further improvement are discussed.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.33 no.2
• /
• pp.160-164
• /
• 2013

A laser ultrasonic inspection system is a non-contact inspection device which generates and measures ultrasonics by using laser beam. A laser ultrasonic inspection system provides a high measurement resolution because the ultrasonic signal generated by a pulse laser beam has a wide-band spectrum and the ultrasonic signal is measured from a small focused spot of a measuring laser beam. In this study, galvanic corrosion phenomenon was measured by non-destructive and non-contact method using the laser. The case of mixed foreign material on the part of corrosion was assumed and laser ultrasonic experiment was conducted. Ultrasonic was generated by pulse laser from the back side of the specimen and ultrasonic signal was acquired from the same location of the front side using continuous wave laser and Confocal Fabry-Perot Interferometer(CFPI). The characteristic of the ultrasonic signal of exist foreign material part was analyzed and the location and size of foreign material was measured.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.272-273
• /
• 2003

링레이저 자이로스코프(Ring Laser Gyroscope-이하 RLG)는 비행기, 유도무기, 선박, 지상무기 등의 관성항법장치(Inertial Navigation System)에 사용되는 각속도 센서로서 항체의 위치와 자세 정보를 제공하는 핵심 구성품 중의 하나이다. 각속도 검출 원리는 삼각형 또는 사각형의 공진기에 He과 Ne을 혼합한 이득매질을 사용하여 서로 반대방향으로 회전하는 두 개의 레이저 빔을 발생시켜서 Sagnac 효과에 의해 외부의 회전 입력을 받을 때 서로 다른 광 경로의 차이로 인한 두 빔의 간섭으로 회전각을 검출한다. (중략)

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.310-311
• /
• 2000

Jo Bessel 빔은 무회절 빔으로서 빔이 전파해 가면서 강도 분포의 변화가 없는 빔이다.$^{[1]}$ 이 베셀빔을 구현하기 위해서는 무한대의 크기를 갖는 수렴렌즈를 사용하여야 하기 때문에 완벽한 베셀빔을 구현할 수는 없다. 그러나 원고리형 슬릿$^{[3]}$ , Axicon 및 Computer -Generated Hologram(CGH)을 사용하여 근사적인 Bessel 빔을 만들 수 있다. 본 실험에서는 Negative Branch Unstable Resonator(NBUR) 고리형 Nd:YAG 공진기와 scraper 출력경을 사용하여 원고리형 출력광을 얻으며, 이에 의한 Bessel 빔을 구현 하기 위한 이론적인 배경과 이의 전산시늉을 시도하고, 실험결과와의 비교, 분석하였다. (중략)