• 한국정밀공학회지
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• 제15권5호
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• pp.93-99
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• 1998

Although laser interferometer measurement system has advantages of measurement range and accuracy, it has some disadvantages when measurement of multi degrees of freedom of motion are required. Because the traditional error measurement methods for geometric errors (two straightness and three angular errors) of a slide of machine tools measures error components one at a time. It may also create an optical path difference and affect the measurement accuracy. In order to identify and compensate for geometric errors of a moving rigid body in real time processes, an on-line error measurement system for simultaneous detection of the five error components of a moving object is required. Using laser alignment technique and some optoelectronic components, an on-line measurement system with 5 degrees of freedom was developed for the geometric error detection in this study Performance verification of the system has been performed on an error generating mechanism. Experimental results show the feasibility of this system for identifying geometric errors of a slide of machine tools.

• 한국광학회지
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• 제16권6호
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• pp.547-552
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• 2005

광간섭 단층촬영(OCT)용으로 원통형 압전소자(PZT)와 단일모드 광섬유를 이용한 광경로 지연기를 제작하여 그 특성을 분석하였다. 광경로 지연기에서 발생하는 편광모드 분산은 편광조절기로 조절하였고, 열요동을 2중 광경로 지연기를 구성하여 최소화하였다. 이중 광경로 지연기는 단일 광경로 지연기에 비해 2배의 측정 깊이와 속도를 구현하여 $18.6\pm0.5{\mu}m$의 해상도. 측정 깊이 1.68 mm, 측정 녹도 360.4 mm/s를 각각 얻었다.

• 한국광학회지
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• 제17권2호
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• pp.159-164
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• 2006

원통형의 압접소자를 이용한 광지연선을 사용하여 광 간섭형 단층촬영 시스템을 제작하였다. 광지연선은 18 m 길이의 단일 모드 광섬유를 압전소자의 둘레에 134회 감아 구성하였으며 0.78 mm의 광경로 길이변화를 얻었다. 제작한 광 간섭형 단층촬영 시스템은 신호 대 잡음비 96.9 dB, 종방향 분해능 $18.6{\pm}0.5\;{\mu}m$, 횡방향 분해능 $5\;{\mu}m$의 특성을 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.405-406
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• 2008

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.451-454
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• 1990

Room temperature cw operations of a standing wave and a unidirectional Ti:Sapphire laser pumped by a $Ar^+$ laser have been demonstrated in the same pumping cavity configuration. Laser emission at 790 nm was excited with all-line $Ar^+$ laser pump for both cavities. The maximum output power was found to be 600 mW in the standing wave cavity and 210 mW in the ring cavity. Values of (83 ${\pm}$ 10) % for the internal quantum efficiency and (3.0 ${\pm}$ 0.5) % for the round-trip cavity loss for standing wave cavity are obtained from the thresholds and slope efficiencies measured with 2.4 and 11.2 % optput couplers. The measured cavity-loss value at 790 nm gives a meterial figure of merit (FOM) to be 146. Unidirectional operation of the ring Ti:Sapphire laser will be discussed.

• 한국레이저가공학회지
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• 제12권1호
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• pp.19-24
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• 2009

Because of its fast and precise welding performance, laser welding is becoming a new excellent welding method. However, the precise focusing and robust seam tracking are required to apply laser welding to the practical fields. In order to laser weld a type of T joint like a circular pipe on a square pipe, which could be met in the three dimensional structure such as an aluminum space frame, a visual sensor system was developed for automation of focusing and seam tracking. The developed sensor system consists of a digital CCD camera, a structured laser, and a vision processor. It is moved and positioned by a 2-axis motorized stage, which is attached to a 6 axis robot manipulator with a laser welding head. After stripe-type structured laser illuminates a target surface, images are captured through the digital CCD camera. From the image, seam error and defocusing error are calculated using image processing algorithms which includes efficient techniques handling continuously changed image patterns. These errors are corrected by the stage off-line during welding or teaching. Laser welding of a circular pipe on a square pipe was successful with the vision tracking system by reducing the path positioning and de focusing errors due to the robot teaching or a geometrical variation of specimens and jig holding.

• 한국염색가공학회지
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• 제35권2호
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• pp.121-127
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• 2023

In this study, a comprehensive investigation was conducted on the morphological and property changes of laser-induced nanocarbon (LINC) as a function of laser process parameters. LINC was formed on the surfaces of polyimide films with different backbone structures under various process conditions, including laser power, scan speed, and resolution. Three different forms of LINC electrodes (i.e., continuous 3D porous graphene, wooly nanocarbon fibers, line cut) were formed depending on the laser power and scan speed. Furthermore, heteroatom doping induced from the chemical structure of the polyimide during laser patterning was found to be effective in modifying the electrical properties of LINC electrodes. The LINC surfaces exhibited different microstructures depending on the laser beam resolution under constant laser power and scan speed, allowing for controllable surface wettability. The correlation between the chemical structure of the polymer substrate, laser process parameters, and carbonized surface properties in this study is expected to be utilized as fundamental understanding for the manufacturing of next-generation carbon-based electronic devices.

• 한국광학회지
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• 제17권1호
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• pp.60-67
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• 2006

본 논문에서는 I자형과 U자형의 변압기를 각각 사용한 펄스형 고전압 전원에 의해 대기압에서 동작되는 파장 337.1 nm인 질소레이 저의 방전간극과 레이저 관에 각각 광섬유를 설치하고, 이를 통해 나오는 빛을 핀 다이오드를 이용하여 선전리 현상을 직접 관측하고 출력특성을 조사하였다. 레이저 출력이 안정되고 높아질수록 선전리 현상을 뚜렷이 관측할 수 있었고, 레이저 출력은 I자형 변압기보다는 U자형의 변압기를 사용하였을 때 높은 출력과 안정성을 얻었으며, 또한 펄스 방전의 예비동작 시간도 U자형이 1/3 정도 짧았다. U자형의 변압기를 사용하고 출력창의 반사율 $40\%$, 반복율 10 Hz, 레이저 관내에서 질소기체의 유동률이 4 ${\iota}$/min, 방전간극 내에서 질소기체의 유동율이 1500 cc/min, 방전간극 전극 거리 3.0 mm, 레이저 관 내 전극거리 5.0 mm 일 때, 안정성이 $2.7\%$인 $36{\mu}J$의 출력을 얻었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.319-321
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• 2004

We report on progress in developing high-power excimer lasers as well as UV-optics for creating low-temperature poly silicon (LTPS). A new high-power excimer laser offers 315 Watts with high pulse to pulse energy stability. Larger substrates can now be processed in better quality with either the SLS process or the new optics for line beam excimer laser annealing.

• 한국정밀공학회지
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• 제17권6호
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• pp.17-24
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• 2000

1960년 Jawan 등이 1.15㎛ 파장을 포함한 6개의 발진파장을 갖는 He-Ne 레이저의 연속 발진을 성공시킨 이후 레이저는 단색성이나 빛의 진직성을 이용하는 계측에서 특히 정밀길이측정에서 매우 중요하게 사용되고 있다. He-Ne 레이저의 발진선폭은 80㎑로써 길이표준기로 사용되었던 Kr-86 스펙트럼선의 선폭(400㎒)의 5,000 분의 1에 해당되는 매우 좁은 선폭을 갖고 있다.(중략)