• Korean Journal of Optics and Photonics
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• v.9 no.1
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• pp.15-19
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• 1998

We have present an all-optical technique to significantly reduce the dispersion penalty of a spectrum-sliced channel in high-speed and long-distance transmissions. We have reduced the necessary optical bandwidth for the 2.5 Gb/s incoherent light transmission down to 0.1 nm by expanding the optical bandwidth of a received signal. The optical bandwidth expansion was realized using the intra-channel fiber four-wave mixing at the receiver resulting in an improvement of th signal-to-noise ratio of the received light channel. We have successfully demonstrated the transmission of a 2.5 Gb/s NRZ signal with the 0.1 nm bandwidth over a 300 km dispersion-shifted fiber. An error floor occurs at $1{\times}10^{-5}$ BER without the optical bandwidth expansion. With the optical bandwidth expansion, however, the error floor decreases to less than $1{\times}10^{-10}$. The transmission penalty was less than 0.5 dB at $1{\times}10^{-10}$ BER. To our knowledge, the optical bandwidth of 0.1 nm used in our experiment is the narrowest optical bandwidth reported so far.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.359-360
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.425-426
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.423-424
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.121-122
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.369-370
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.63-64
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.365-366
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• 2008

The spontaneous emission spectrum and the radiative recombination coefficient were analytically derived from the two band model for both the bulk (3-D) and the quantum well(2-D) structures of GaN-based Wurtzite crystal.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.487-487
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• 2006

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.119-124
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• 2008

In recent years, gradually increasing interest has been directed to the use of terahertz technology in nondestructive testing and non-invasive measurements, and terahertz time domain spectroscopy (THz-TDS) has become a key technology in such applications. This paper deals with the terahertz pulse generation from cadmium telluride via optical rectification process of femto-second infrared laser pulses. The measured terahertz spectrum is compared with the result of model calculation based on space-time domain nonlinear Maxwell equations for coherent frequency mixing process. The propagation process of terahertz and infra-red pulses in the material as well as the surface interference and free space diffraction effects are also considered. The experimental results are in good agreements with the calculated spectrum.