• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.240-241
• /
• 2001

주파수 위상 간섭계를 이용한 전기장 재구성 방법(SPIDER)은 현재의 전자장치로 분해 해낼 수 없는 짧은 펄스의 시간적 특성을 광학적 방법을 사용하여 분해 해내는 기술이며, 다음과 같은 순서로 시간 영역의 펄스를 재구성한다 ： 1)주파수 간섭계(spectral inteferometry)를 사용하여 일정한 시간지연을 갖는 동일한 펄스 쌍을 만든다. 2)분산이 큰 물질(highly dispersive material)이나 에돌이 발 쌍(pairs of gratings)을 사용하여 크게 chirping되며 200배 전후로 펄스폭을 늘인 펄스를 생성한다. (중략)

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.5 s.170
• /
• pp.21-27
• /
• 2005

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.4
• /
• pp.141-145
• /
• 2011

We theoretically investigated dispersion tolerance of an optical duobinary transmitter employed a Mach-Zehnder modulator and an optical filter. Compared to the optical transmitter based on a Mach-Zehnder modulator and an optical delay interferometer by optimizing the applied voltage for improving the dispersion tolerance, the demonstrated duobinary transmitter provides improved receiver sensitivity and higher dispersion tolerance while maintaining narrow spectral bandwidth.

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.02a
• /
• pp.105-106
• /
• 2008

• Journal of the Korean Society for Precision Engineering
• /
• v.34 no.4
• /
• pp.259-264
• /
• 2017

Spectrally resolved interferometry (SRI) is an attractive technique to measure absolute distances without any moving components. In the spectral interferogram obtained by a spectrometer, the optical path difference (OPD) can simply be extracted from the linear slope of the spectral phase. However, SRI has a fundamental measuring range limitation due to maximum and minimum measurable distances. In addition, SRI cannot distinguish the OPD direction because the spectral interferogram is in the form of a natural sinusoidal function. In this investigation, we describe a direction determining SRI and propose the optimal conditions for determining OPD direction. Spectral phase nonlinearity, caused by a dispersive material, effects OPD direction but deteriorates spectral interferogram visibility. In the experiment, various phase nonlinearities were measured by adjusting the dispersive material (BK7) thickness. We observed the interferogram visibility and the possibility of direction determination. Based on the experimental results, the optimal dispersion conditions are provided to distinguish OPD directions of SRI.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.565-568
• /
• 2005

We describe a new scheme of dispersive white-light interferometer that is capable of measuring the thickness profile of thin-film layers, for which not only the top surface height profile but also the film thickness of the target surface should be measured at the same time. The interferometer is found useful particularly for in-situ inspection of micro-engineered surfaces such as liquid crystal displays, which requires for high-speed implementation of 3-D surface metrology.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.105-106
• /
• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.23-24
• /
• 2006

We present a dispersive scheme of white-light interferometry that enables not only to perform tomographical measurements of thin-film layers but also to measure a refractive index without mechanical depth scanning. The interferometry is found useful particularly for in-situ 3-D inspection of micro-engineered surfaces such as liquid crystal displays, semi-conductor and MEMS structure, which requires for high-speed implementation of 3-D surface metrology.

• Proceedings of the Optical Society of Korea Conference
• /
• 2007.02a
• /
• pp.17-18
• /
• 2007

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.07a
• /
• pp.24-25
• /
• 2005