• Korean Journal of Optics and Photonics
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• v.3 no.4
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• pp.280-287
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• 1992

The nonlinear optical properties of semiconductors and semiconductor microstructures have been the subject of intense research, not only from a fundamental physics point of view, but also for their potential applications to future opto-electronic devices. In this paper, steady-state and time-resolved nonlinear optical spectroscopic techniques to investigate the microscopic world of semiconductor materials were briefly described.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.964-970
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• 2002

We synthesized three kinds of chromophores incorporating aromatic quinoline unit as a $\pi-conjugated$ bridge in order to prepare more thermally stable nonlinear optical (NLO) chromophores than general stilbene unit. The NLO poly(methylmethacrylate) copolymer, polyimides, and polyester were successfully synthesized by these corresponding quinoline-based monomers. Their physical and optical properties were investigated by thermogravimetry, gel permeation chromatography, ultraviolet-visible spectroscopy, second harmonic generation (SHG) and electro-optic (EO) measurement. All the polymers exhibited better thermal stability,however their NLO activity was a little lower than that of general stilbene-based NLO polymers. Among three kinds of polymers, the PMMA copolymer with quinoline chromophores had the largest SHG coefficient d33 value of 27 pm/V (at 1.064 $\mu\textrm{m})$ and EO coefficient r33 value of 6.8 pm/V (at 1.3 $\mu\textrm{m}$).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.315-323
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• 1998

$TiO_2$films of rutile and anatase phase have been prepared on silica glass substrates by the sol-gel method using $Ti(i-OC_3H_7)_4$. The effect of additives on the polymorph of $TiO_2$film has been examined in view of degree of crystallization. Third-order nonlinear optical properties of the both film have been investigated by the third harmonic generation method. The measured 3rd order nonlinear optical susceptibility of rutile and anatase thin films were about $1.4{\times}10^{-12}$ and $9.7{\times}10^{-13}$ esu, respectively.

• Proceedings of the Optical Society of Korea Conference
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• 1991.07a
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• pp.129-134
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• 1991

반도체 물질들은 일반적으로 흡수 끝 (absorption edge) 근처에서 비선형 광학 계수가 이례적으로 크고, 그 반응 속도가 빠른 특성을 갖고 있다. 본 논문에서는 반도체와 반도체 미세구조에 있어서의 비선형 광학적 특성 및 초고속 논리 광소자로서의 응용을 고찰하였다.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.117-118
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.40-41
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.32-32
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• 1997

• Journal of the Korean Ceramic Society
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• v.34 no.9
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• pp.941-948
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• 1997

CuCl nanocrystallites dispersed nonlinear optical silica and borosilicate glasses were fabricated by sol-gel process. CuCl powder was dissolved in TEOS(Si(OC2H5)4) and TMB((CH3O)3B), precursors of silica and borosilicate glasses, with ethanol, water and HCl, and precipitated through the heat treatment in the matrix glass. The optical properties of CuCl doped glasses were measured using the spectrophotometer at room temperature and low temperature(77K); Z1, 2 and Z3 exciton peaks from the absorption spectra, were observed at about 370 nm and 380 nm, respectively. The average radius of nanocrystallites, calculated from the blue shift of Z3 excitons, was measured according to annealing temperature and time. The precipitation temperature of CuCl nanocrystallites was decreased when boron was added to silica glass. Increase of annealing temperature and time made average radius of nanocrystallites saturated about 2 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.491-496
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• 2010

The relaxation behavior of aligned electric dipoles in a mixed polymer of P2ANS with P(VDF-TrFE) is studied with optical second harmonic generation (SHG). In this work, a macroscopic noncentrosymmetry of the spin coated film was achieved by an electrical poling. The relaxation of induced polar order of nonlinear optic(NLO) chromophores after poling leads to an insufficient long-term stability of NLO properties. In this work, we develop a new technique to suppress such kind of dipole relaxation in a poled polymer. We found that the poled dipoles in a NLO polymer were effectively immobilized by the internal electric field created by a thermally annealed ferroelectric polymer. The long-term stability in a mixed system of NLO polymer/ferroelectric polymer was successively accomplished by a series of thermal treatments applied to the mixed polymer system at a temperature of $140^{\circ}C$ for at least 1hour after poling.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5A
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• pp.316-322
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• 2003

We theoretically analyze the properties of nonlinear distortion due to modulation instability (MI), which is a major factor of performance degradation in optical amplified transmission systems, and propose an optical link structure to compensate MI based on the analysis. The proposed MI compensating link structure is composed of optical phase conjugators (OPCs) and dispersion compensating fibers (DCFs) in order to suppress nonlinear effects in optical transmission links. It has been confirmed through computer simulations that the performance of the proposed compensation scheme is superior to that of conventional compensation schemes for 500 km transmission.