http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
레이저 멀티 펄스 중첩과 회절광학소자를 이용한 숨쉬는 필름 고속 가공 기술
유동윤,최훈국,손익부,노영철,이용탁,김영재,김영한,강호민,노지환,Yoo, Dongyoon,Choi, Hun-Kook,Sohn, Ik-Bu,Noh, Young-Chul,Lee, Yong-Tak,Kim, Young-Jae,Kim, Young-Han,Kang, Ho-Min,Noh, Jihwan 한국레이저가공학회 2014 한국레이저가공학회지 Vol.17 No.3
In this paper, we studied a machining method using a diffractive beam splitter (DBS) and multi- pulse repeated radiation for breathable film. We fabricated micro-grooves on polypropylene (PP) films using multi-pulse radiation and one-shot radiation (radiating pulses at once) and a DBS. In the result, width and depth of the PP film using multi-pulse repeated radiation were more precisely controllable. Therefore, this method can be applicable to in manufacturing breathable film precisely at a high speed.
유동윤,최훈국,손익부,노영철,신중원,Yoo, Dongyoon,Choi, Hun-Kook,Sohn, Ik-Bu,Noh, Young-Chul,Shin, Jung-Won 한국레이저가공학회 2015 한국레이저가공학회지 Vol.18 No.1
In this paper, controlling shape of optical fiber tip for endoscope was investigated for eliminating blind spot. The blind spot of endoscope is generated by divergence angle of optical fiber, so it is easy to generate blind spot when tightly focusing. In order to eliminate this region, fiber tip is necessary to be controlled as convex or concave. Illumination simulation of convex and concave type of fiber tip in the endoscope was in progress, so the distance of non- blind region was investigated in each case. As well as the simulation, the tip was fabricated as concave shape by UV laser machining. Then the beam radiation was measured to observe the blind region. The result showed that controlling the fiber tip as convex or concave shape makes the narrow blind region of illumination in endoscope.
CO<sub>2</sub> 레이저를 이용한 음각 원뿔 구조 광섬유 팁 가공 최적화 연구
유동윤,최훈국,손익부,노영철,정덕,김영섭,이호,김창환,Yoo, Dongyoon,Choi, Hun-Kook,Sohn, Ik-Bu,Noh, Young-Chul,Jung, Deok,Kim, Young-Sup,Lee, Ho,Kim, Chang-Hwan 한국레이저가공학회 2015 한국레이저가공학회지 Vol.18 No.3
A helical fabricating method using $CO_2$ laser was utilized for producing cone-shaped structure on a silica substrate. Output power and the number of scanning radiation were modified in order to control the structure. The experiment shows that the depth and width of cone-shape were increased with higher output power of the laser and the number of scanning. We demonstrate fabrication of multidirectional side-firing optical fiber with diameter of 440 um using the $CO_2$ laser fabrication technique.
펨토초 레이저를 이용한 PLC 가변광감쇠기 특성 향상을 위한 열간섭 차단 트렌치 가공 기술
유동윤,최훈국,손익부,김영식,김수용,김완춘,김진봉,Yoo, Dongyoon,Choi, Hun-Kook,Sohn, Ik-Bu,Kim, Youngsic,Kim, Suyong,Kim, Wanchun,Kim, Jinbong 한국광학회 2016 한국광학회지 Vol.27 No.4
본 논문에서는 다채널 가변광감쇠기에서 발생하는 열간섭 효과를 차단하여 광효율을 높이기 위하여 펨토초 레이저를 이용하여 트렌치를 가공하였다. 채널간 열간섭으로 인한 광감쇠 제어효율 하락을 막기 위하여, 가변광감쇠기 채널 사이에 펨토초 레이저로 트렌치의 폭과 깊이를 다르게 하여 가공하였고, 적용된 각 칩을 모듈화하여 전류에 따른 광감쇠율 변화를 관찰하였다. 그 결과 광감쇠를 위해 가해진 열이 주변채널에 영향을 매우 작게 미치는 것을 확인하였고, 뿐만 아니라 작은 전류에 광감쇠율이 민감하게 변화하는 것을 확인할 수 있어 효율적인 소자로서 개발 가능함을 확인하였다. In this paper, a trench structure was fabricated by femtosecond-laser machining to eliminate thermal crosstalk in a multichannel variable optical attenuator (VOA), to prevent decreasing attenuation efficiency of the VOA. Trenches of a variety of widths and depths were fabricated on the VOA chips by femtosecond-laser processing. After the machining, attenuation according to current change was observed in each VOA chip module with trenches. As a result, we could observe high responsivity of attenuation and low power consumption, and that the heat of each channel barely influenced other channels.
최훈국,유동윤,손익부,노영철,김영식,김수용,김완춘,김진봉,Choi, Hun-Kook,Yoo, Dongyoon,Sohn, Ik-Bu,Noh, Young-Chul,Kim, Young-Sic,Kim, Su-yong,Kim, Wan-Chun,Kim, Jin-Bong 한국레이저가공학회 2015 한국레이저가공학회지 Vol.18 No.1
In this paper, micro trench structure is fabricated by femtosecond laser for inserting optical reflecting wavelength filter in planar waveguide. The width and depth of the trench is controlled by femtosecond laser machining condition. Also, large scale of single channel with 500um and 1000um on silica plate is fabricated by femtosecond laser, and roughness of the channel surface is polished by $CO_2$ laser for the insertion of the filter. Then, the characteristic of the planar waveguide inserted the filter is verified.
열 하중 기반의 리츠벡터와 순차적 센서위치 선택방법을 이용한 강건하고 효율적인 열 오차 모델링
현재엽(Jaeyub Hyun),유동윤(Dongyoon Yoo),이선규(Sun-Kyu Lee),왕세명(Semyung Wang) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
Thermal deformations are among the most significant factors to errors generation of machine tool, this degrades the performance and accuracy of the machine tool. There are many methods to reduce the thermal deformation, such as structural designs to minimize thermal deformation, approaches to block and/or suppress thermal source, and thermal error compensation techniques to estimate and control thermal deformation. Among these, thermal error compensation techniques have been realized as the most successful method and actively studied. Securing of robustness and effectiveness of the thermal error modeling is directly correlated to the better compensation results. Most of the current thermal error modeling methods is highly dependent on measured data, and cannot consider mechanisms of the thermal deformation due to the thermal-structural interaction effect. In this paper, therefore, a novel and innovative strategy that can select the optimized thermal sensor placement and thermal error modeling method are proposed based on thermal load dependent ritz vectors. Operation state of the actual machine tool and thermal source variation are continuously changing according to the time. Thus, the various boundary conditions are applied to properly deal with these variations. The Wilson’s Ritz algorithm is used for generating the thermal load dependent Ritz vectors. Finally, for various 2D and 3D systems such as heat pipe and spindle, both existing thermal errors modeling method to use the eigenvectors and proposed method to use thermal load dependent ritz vectors are compared and investigated. Through this, the robustness and effectiveness are verified.