• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.431-434
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• 2005

LabVIEW를 사용하여 광섬유에서의 극초단 펄스 전파의 특성에 관한 연구를 수행하였다. 수치해석을 위해 1550nm의 극초단 광원을 Silica재질의 광섬유에 도파시키고 Split Step Fourier 방법을 이용하여 전파특성을 계산하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.324-326
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• 2004

We have obtained ultra-short pulses with a wavelength of 616 nm from a Distributed Feedback Dye Laser pumped by excimer laser. Using the second harmonic generation, we obtained ultra-short pulse at 308nm in ultraviolet region and also performed amplification in 3 stages of XeCl amplifiers.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.271-271
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• 2016

highly doped N-type 실리콘 기판 위에 극초단 펄스 레이저를 이용하여 LIPSS (Laser-Induced Periodic Surface Structure) 패턴을 형성하였다. 형성된 LIPSS 구조는 $15{\mu}m$와 500 nm 주기를 가지는 ripple로 형성이 되었고 이 구조를 형성하기 위해서 사용된 레이저는 Satsuma HP2, Amplitude syst?mes 이다. LIPSS 패턴을 가지는 기판 위에는 유기반도체 물질인 pentacene을 50 nm로 열 증착방법을 통해 박막을 형성하여 유기박막트랜지스터를 제작하였고, hole mobility를 측정하였다. LIPSS 패턴을 가지는 실리콘 기판과 pristine 실리콘 기판 위의 pentacene의 morphology를 AFM으로 관찰하고 유도된 구조를 연구하였다.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.7-12
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• 2010

Due to the extremely short interaction time (< $10\times10^{-12}$sec) between laser pulse and material, which enables the minimization of heat affection, ultrafast laser micro-machining has rapidly widened its applications. In this paper, the characteristics of ultrafast laser micro-machining have been reviewed and experimentally demonstrated in laser drilling of silicon wafer and in laser cutting of rigid PCB.

• The Magazine of the IEIE
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• v.17 no.5
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• pp.53-65
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• 1990

• The Optical Journal
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• s.120
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• pp.69-73
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• 2009

본 논문에서는 레이저 가공의 문제점인 FPCB에서의 낮은 생산성과 열영향을 보완하기 위한 실험내용을 다루고 있으며 극초단펄스 레이저와 나노초 UV레이저를 이용하여 FPCB의 기반재료인 FCCL(Flexible Copper Clad Laminate)를 절단하며 생산성 및 열영향을 비교하고 있다. 나노초 레이저는 피코초 레이저 경우에 비해 가공속도가 빨라 양산공정에 적합하며 피코초 레이저는 나노초 레이저에 비해 용융물이 적게 발생하여 다층/고집적화에 적합하나 출력이 낮은 단점이 있어 현단계에서의 양산가공으로의 적용이 어렵다는 결론이다. 그러나 여러 선도 업체에서 극초단 펄스레이저의 고출력화에 대한 시도가 이뤄지고 있으므로 생산성의 문제는 빠른 시일 내에 해결될 것으로 판단된다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.620-623
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• 2003

The material processing by using ultrashort pulse laser, in recently, is actively applying into the micro machining and nano-machining technology since ultrashort pulse has so faster than the time which the electrons energy absorbing photon energy is transmitted to surrounding lattice-phonon that it has many advantages in point of machining. The micro machining of metallic thin film on the plain glass is widely used in the fields such as mask repairing for semiconductor, fabrication of photonic crystal, MEMS devices and data storage devices. Therefore, it is important to secure the machining technology of the sub-micron size. In this research, we set up the machining system by using ultrashort pulse laser and conduct on the Cr 200nm thin film ablation experiments of spot and line with the variables such as energy, pulse number, speed, and so on. And we observed the characteristics of surrounding heat-affected zone and by-products appeared in critical energy density and higher energy density through SEM, and also examined the machining features between in He gas atmosphere which make pulse change minimized by nonlinear effect and in the air. Finally, the pit size of 0.8${\mu}{\textrm}{m}$ diameter and the line width of 1${\mu}{\textrm}{m}$ could be obtained.

• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.245-250
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• 2002

We study numerically the temporal evolutions of two orthogonally polarized pulses with width less than 100fsec in all-optical phase-shift switches. We analyze the complicated interplay between a soliton pulse and a higher-order soliton pulse, including the self-and the cross-Raman scattering and the walk-off effect. We also investigate the influence of these interactions on switching performance, including pulse-shape, phase-shift distribution, and contrast ratio. In particular we show that an optical fiber with a typical birefringence (Δn : 2.4$\times$10$^{-5}$ ) can be used with good switching performance in such all-optical switches.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.126-130
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• 1991

다이오드 레이저의 능동형 모드락킹 구조로부터 극초단 광펄스를 발생시켰다. 모드락킹된 광펄스를 얻기 위해 다이오드 레이저의 한쪽 면을 무반사 코팅했으며, 얻어진 광펄스의 폭(FWHM)은 22psec였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.6
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• pp.8-18
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• 2002

We study complicated nonlinear interactions of two orthogonally polarized pulses with pulse-width of less than 100fsec in the all-optical phase-shift switches, which use soliton pulse-train and fiber-splicing for control pulse to obtain multi-collisional $\pi$-phase-shift and consider Raman response function. We investigate switching performance in various input parameters such as input pulse-width and birefringence of fiber, and find optimum initial conditions for good switching performance in such all-optical switches.