• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1253-1309
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• 2002

1,3,5-Tricyano-2,4,6-tris[2-(thiophen-2-yl)vinyl]benzene derivatives have been synthesized as a new type of octupolar nonlinear optical molecules and their linear and nonlinear optical properties were determined. The λmax values increa sed with the conjugation length and as the conjugation bridge was changed from phenyl to thienyl group. For phenyl and thiophene derivatives, the b value increased with conjugation length. In contrast, the $\beta$ values of the thiophene derivatives were much smaller than the corresponding phenyl derivatives.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.24-30
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• 2002

This paper demonstrates a comparison of linear and nonlinear analyses for thermo-optic effects of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include theoretical analyses and experiment of the etched planar waveguide Bragg grating optical temperature sensor. Theoretical models with nonlinear than linear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1353-1364
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• 1996

Recently semiconductor doped glasses have attracted attention as nonlinear optical materials because of their large third order nonlinear optical properties. The transparent and homogeneous CdS-doped SiO2 glass thin films were obtained by the dip=coating process of the sol-gel method. Thin films were consisted of glasses containing CdS microcrystallites which were formed by dissolved Cd2+ and S2- ions in a SiO2 matrix solutions. A subsequent thermal treatment of this samples led the formation of colloidal agglomerates and finally of microcrystallites. The size of CdS microcrystallites was about 4 to 15 nm after thermal treatments at various heating conditions. From the optical absorption spectra of the CdS-doped SiO2 glass films it was found that the absorption edge was blue-shifted compared with that of the bulk CdS crystal(~2, 4 eV) and that the amount of energy shift was inversely proportional to the crystal size. And the band gap energy increased with the decrease in crystallite size indicating that the quantum size effects occured.

• 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.

• Proceedings of the Optical Society of Korea Conference
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• 1995.06a
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• pp.161-168
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• 1995

Nonlinear optical absorption in solid films of poly(3-octyl thiophene) (P3OT) sensitized with methanofullerene was inverstigated for wacelengths from 620 to 960nm. The nonlinear absorption is ehnanced over that in either of the component materials by more than two orders orders of magitude at 760nm. The large nonlinearity results from effient photoinduced interm olecular charge transfer from P3OT to methanofullerene, followed by absorption in the charge separated excited state. P3OT/fullerene films are promising as reverse saturable absorbers and the optical limiting performance is demonstrated at 760nm.

• 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 Sensor Science and Technology
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• v.15 no.4
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• pp.297-301
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• 2006

We have fabricated a multi-mode nonlinear plastic optical fiber (POF) using organic nonlinear optical materials and demonstrated the propagation of light. The refractive indices of core and cladding are 1.5240 and 1.5172. We made a POF preform by rod-in tube method. The core diameter of the fabricated POF is about $30{\mu}m$. We evaluated the temperature characteristics of POF. The sensitivity is $0.345{\;}mW/^{\circ}C$ and the linearity of sensor was good.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2049-2054
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• 2006

This paper demonstrates a comparison of linear and nonlinear analyses for thermo-optic effects of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include theoretical analyses and experiment of the etched planar waveguide Bragg grating optical temperature sensor, Theoretical models with nonlinear than linear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

• Proceedings of the Optical Society of Korea Conference
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• 1998.08a
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• pp.76-77
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• 1998

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.6-7
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• 2001