• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.242-243
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• 2001

고출력 펨토초 레이저 기술은 커렌즈 모드록킹 기술, Ti：sapphire 이득매질의 개발, chirped pulse amplification (CPA) 등의 도움으로 1980년대 후반부터 급속히 발전해 왔다. 생성된 펨토초 펄스의 시간적 특성을 정확히 알아내기 위한 방법들도 많이 연구되어 주파수 분해 괌게이팅(FROG)이나 주파수위상 간섭계(SPIDER) 등의 방법들이 기존의 자체상관계를 대체하게 되었다. 극초단 레이저 펄스는 넓은 스펙트럼을 갖고 첨두출력이 높기 때문에 매질이나 광학계를 지나면서 군지연분산, 자체위상변조 등의 효과에 의한 시간적 위상변화가 쉽게 생긴다. (중략)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1157-1166
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• 2001

In this paper, we investigated the degree of compensation for optical pulse shape distortion due to both chromatic dispersion and SPM(self phase modulation) in high speed optical transmission system with dispersion shift fiber. We adopted the power symmetric MSSI(mid-span spectral inversion) as compensation method. We used EOP(eye-opening penalty) parameter in order to evaluate the compensation efficiency of distorted optical pulse. We evaluated input signal power range being able to maintain stable reception performance in the case of various chirp parameter of modulated optical pulse. And, in order to verify the applicable to wideband WDM system, we evaluated the wavelength range being able to maintain stable reception performance through the EOP calculation of various dispersion coefficient of first fiber D$\_$11/. We showed that proposed MSSI is effective compensation method to down chirped optical pulse transmission rather than up chirped optical pulse transmission in anomalous dispersion range. And we showed that this method have possibility of relative high power transmission and wideband transmission in WDM system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.137-138
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• 2008

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.135-138
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• 2003

A chirped-pulse amplification femtosecond Ti:sapphire laser operating at 1 KHz has been developed. The laser system consisted of a long-cavity femtosecond oscillator, a four-pass grating pulse stretcher, two multi-pass amplifiers and a double-pass grating pulse compressor. Thermal lensing at the amplifiers was reduced by cooling Ti:sapphire crystals using Peltier coolers. Gain narrowing and residual phase errors were compensated for by the use of an acousto-optic pulse shaper. The final laser output had an energy per pulse of 2.0 mJ and a pulse duration of 19.5 fs, reaching 0.1 TW at 1 KHz.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1075-1080
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• 2003

We have investigated femtosecond coherent vibrational motions of Zn(II)-5,15-diphenylporphyrin in toluene using chirp-controlled ultrashort pulses. The oscillatory features superimposed on the temporal profiles of the pump-probe transient absorption signal are affected by the chirping and energy of excitation pulses. Using chirp- and excitation energy-controlled femtosecond pulses, we are able to obtain information on the structural changes between the electronic ground and excited states based on a comparative analysis of the Fouriertransformed frequency-domain spectra retrieved from the oscillatory components with the ground state resonance Raman spectra and normal mode calculations.

• Korean Journal of Optics and Photonics
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• v.10 no.1
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• pp.58-63
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• 1999

A 10 GHz harmonically mode-locked semiconductor-fiber ring laser was implemented using a semiconductor optical amplifier at $1.5\mu\textrm{m}$ The laser pulse has 13~18 ps pulse duration, 0.4~0.6 nm spectral width and was positively chirped. The output pulse with an average power of 4 dBm was compressed to 6.8 ps using 2 km long standard single mode optical fiber.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.60-66
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• 2005

In this paper, we propose the basic measurement method of a 3D digitizer using a CCD camera in detail. In the localization measurement with a CCD camera, the effect of the background light and the sensitivity consideration are always problems in realizing a high precision. In this research, a new measurement principle is proposed in which the pulse compression technique known in radar is used to eliminate the effect of background light even under a low intensity light source, and the coordinate values on the CCD camera image plane are determined accurately. From the quantitative evaluation of the S/N ratio improvement and the fundamental experiment, it is verified that a substantial improvement in the S/N ratio is realized for both the background noise and the pixel noise and that a resolution of less than the pixel is sufficiently possible.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.34-35
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• 2003

펨토초 레이저의 개발은 커렌즈 모드록킹 (Kerr-lens mode-locking； KLM) 기술이 티타늄사파이어 이득매질에 적용되면서 1990년대에 들어 급격하게 이루어졌다. 구조가 간단하면서 안정적인 KLM 티타늄사파이어 레이저는 현재 펨토초 레이저 광원의 표준을 이루고 있으며, 처프펄스 증폭 (chirped-pulse amplification； CPA) 방식을 이용하여 소규모의 테라와트급 고출력 펨토초 레이저 제작에도 이용되고 있다. 특히, 1990년대 말에는 CPA 증폭단을 갖춘 KLM 티타늄사파이어 레이저가 상용화되면서 물리, 화학과 같은 기초 분야에서뿐만 아니라 의료용, 산업용으로도 활용이 확대되고 있다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.318-319
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.234-235
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• 2001

최근의 극초단 펄스의 개발의 대부분은 주로 고체 이득매질을 이용하여 근적외선 영역에서 이루어지고 있다 그러나 가시광선인 500～700 nm 파장대역에서는 특성이 좋은 고체 이득매질의 개발이 이루어지지 않아, 가시광선 영역의 극초단 펄스의 개발에 대한 연구는 최근에는 거의 이루어지지 않고 있다. 현재로서 가능한 방법은 티타늄 사파이어 레이저를 이용하여 극초단 펄스를 발생시키고, 이를 CPA(Chirped Pulse Amplification)방법으로 증폭한 다음에 이의 제2고조파 펄스를 얻고, 이를 다시 광파라메트릭 방법으로 가시광선 파장영역의 극초단 펄스를 얻는 방법이 있는데, 이는 대규모의 설비 및 장치를 필요로 한다. (중략)