• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.51-54
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• 2008

Various types of beam distributions of high energy lasers are classified by the mode patterns. We study two dimensional laser initiation of confined energetic materials with multiple beam profiles.

• Korean Journal of Optics and Photonics
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• v.24 no.5
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• pp.224-230
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• 2013

Laser Lift-Off (LLO) is a process that removes a GaN or AIN thin layer from a sapphire wafer to manufacture vertical-type LEDs. It consists of a light source, an attenuator, a mask, a projection lens and a beam homogenizer. In this paper, we design an attenuator and a projection lens. We use the 'ZEMAX' optical design software for analysis of depth of focus and for a projection lens design which makes $7{\times}7mm^2$ beam size by projecting a beam on a wafer. Using the 'LightTools' lighting design software, we analyze the size and uniformity of the beam projected by the projection lens on the wafer. The performance analysis found that the size of the square-shaped beam is $6.97{\times}6.96mm^2$, with 91.8 % uniformity and ${\pm}30{\mu}m$ focus depth. In addition, this study performs dielectric coating using the 'Essential Macleod' to increase the transmittance of an attenuator. As a result, for 23 layers of thin films, the transmittance total has 10-96% at angle of incidence $45-60^{\circ}$ in S-polarization.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2003.05a
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• pp.26-34
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• 2003

• Laser Solutions
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• v.4 no.3
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• pp.11-21
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• 2001

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.05a
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• pp.23-24
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• 1998

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.1018-1021
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• 2009

여기시켜 고출력, 고안정화 레이저 빔 특성을 실험적으로 분석 및 고찰하였다. 실험적 결과 완전한 형태의 선형적인 레이저 빔 특성을 얻을 수는 없었으나 레이저 특성인 거의 선형적인 모양의 그래프 특성이 나타남을 확인할 수 있었다.

• 전기의세계
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• v.45 no.5
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• pp.17-22
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• 1996

PLD 장치는 진공 또는 반응가스가 채워진 챔버안에 다층 박막을 증착시킬 수 있는 여러개의 타겟홀더와 기판홀더가 존재하고 물질을 기화시켜 박막을 증착시키기 위해 외부 에너지원으로 고출력 레이저가 사용되며, 일련의 광학장치들은 타겟표면에 레이저 빔을 접속시키고 주사하기 위해 사용된다. 타겟표면에 접속된 레이저 빔은 타겟표면 물질을 플라즈마 (또는 플룸) 상태로 만들고 이 플룸이 결정화에 알맞는 온도로 가열된 기판위에서 결정구조를 가진 박막을 형성한다. 진공장치와 기화에너지원의 분리는 PLD 시스템을 유연하게 해서 내부적으로 기화에너지원의 사용에 의한 제한없이 다른 동작 모드에 쉽게 적용할 수 있다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.555-556
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• 2008

본 연구에서는 레이저빔 투과를 이용한 본딩 웨이퍼 검사 방법을 제안하고 검사 장치를 설계 구현하였다. 1064nm 파장에서의 정상웨이퍼를 일정한 비율로 투과 하였다. 본딩 불량으로 인한 웨이퍼의 기공은 두께에 따라 투과율이 현저하게 변화하여 기공 부분을 검출하였다. 이러한 기공은 두께의 변화가 있으며 광량의 변화하는 부분이 에어갭으로 인식 카메라로 쉽게 구분이 가능하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.594-601
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• 2009

Shooting simulation systems not only reduce a great amount of expense and time for military exercises but also prevent accidents. In particular, the shooting simulation systems using laser beam have an advantage which is very similar to the shooting exercise that uses real bullets. However, real time technique for laser beam recognition in a target image is necessary. The method proposed in this paper takes a difference image from two adjacent image frames. Then a thresholding is applied on this difference image to discriminate laser beam from background. To decide the threshold value the intensity distribution of background points is modeled assuming normal distribution. Then a noise reduction and a region segmentation are applied on the binary image to find the position of a laser beam. The time complexity of this process depends on the size of an image multiplied by the size of a mask used in the noise reduction process. The experimental result showed that the accuracy of the system was 93.3%. Even in the inaccurate cases the beam was always found in the resultant region.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.168-173
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• 1999

Many sensors such as a laser, CCD camera to obtain 3D information have been used, but most of calibration algorithms are inefficient since a huge memory and an experiment data for laser calibration are required. In this paper, the calibration algorithm of a slit beam laser based on triangulation method is introduced to calculate 3D information in the real world. The laser beam orthogonally mounted on the XY table is projected on the floor. A Cm camera observes the intersection plane of a light and an object plane. The 3D information is calculated using observed and calibration data. This method saves a memory and an experimental data since the 3D information are obtained simply triangulation method.