Junho Mun - Academia.edu (original) (raw)

Papers by Junho Mun

Research paper thumbnail of Procédé et Dispositif D'Extraction De Profondeur Dans Un Appareil Photo À Ouvertures Multiples

Research paper thumbnail of 멀티 애퍼처 카메라에서의 깊이 추출 방법 및 장치

Research paper thumbnail of Optical Fiber With Zero Dispersion Wavelength Shifted to Short Wavelength Region, and Optical Transmission Line and Optical Transmission System Using the Same

Research paper thumbnail of 1933 Transport and trapping of photocharges in liquid crystals placed between photoconductive polymer layers

Research paper thumbnail of Optical fiber, and optical transmission line and optical transmission system using the same

Research paper thumbnail of Photorefractive behaviors in a polymer composite including layered silicates

Applied Clay Science, 2002

Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is ma... more Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is made up of poly(N-vinylcarbazole) (PVK), 2,4,7-trinitro-9-fluorenone (TNF), 4-(4-nitrophenylazo)aniline (DO3), and 9-ethylcarbazole (ECZ), with or without Montmorillonite (MMT) or laponite as a layered silicate. The structures of nanocomposite-PR samples were investigated by X-ray diffraction (XRD). To investigate the PR property, two-beam coupling (TBC) and four-wave mixing experiments were

Research paper thumbnail of Photorefractive effect in nematic liquid crystals doped with nonlinear optical chromophores

LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242), 2001

ABSTRACT

Research paper thumbnail of Synthesis and properties of oligomeric poly(glycidyl ether)s with a carbazole-based multifunctional photorefractive chromophore

Reactive and Functional Polymers, 2000

Novel photorefractive poly(glycidyl ether) oligomers of a carbazole-based multifunctional chromop... more Novel photorefractive poly(glycidyl ether) oligomers of a carbazole-based multifunctional chromophore were synthesized via ring-opening cationic polymerization. This new class of materials showed good solubility in various organic solvents and thermal stability up to 4008C. Optical quality films of excellent transparency at the light wavelength above 430 nm were 213 21 22 obtained by spin-coating or casting. Photoconductive sensitivity of the film was as high as 10 S cm / mW cm at 532 21 nm. Electrooptic coefficients (r) of 5-7 pm V were easily achieved by the contact poling of spin-coated films. As 33 21 evidence of photorefractivity, an asymmetric two-beam coupling gain of 3.2 cm was demonstrated at an electric field of 30 21 V mm with a low-T polymer blend of multifunctional poly(glycidyl ether).

Research paper thumbnail of Organometallic−Organic Hybrid Crystals from Ferrocenyl Dipyridine and Binaphthol:  Different Crystal Structures and Nonlinear Optical Properties Depending upon the Reaction Medium and Optical Purity of Binaphthol

Organometallics, 1999

Molecular recognition between 1, 1'-bis (ethenyl-4-pyridyl) ferrocene (1) and (±)-1, 1-b... more Molecular recognition between 1, 1'-bis (ethenyl-4-pyridyl) ferrocene (1) and (±)-1, 1-binaphthol (2)/(-)-1, 1-binaphthol ((-)-2) has been studied by cocrystallization in different solvents. Single-crystal X-ray structures reveal that cocrystallization of 1 and 2/((-)-2 in ...

Research paper thumbnail of Photo-aligned and photo-conductive polymer layers for photorefractive liquid crystal cells of high transmittance

Optical Materials, 2003

The optical performance of photorefractive cells of liquid crystals strongly depends on the align... more The optical performance of photorefractive cells of liquid crystals strongly depends on the alignment of liquid crystals stabilized by surface states. Two photo-aligned polymer layers with relatively weak anchoring energy were investigated by FT-IR and UV/VIS spectroscopies. The cells without alignment layers showed significant scatterings due to random switching under an applied field. The cells with photo-alignment layers showed the

Research paper thumbnail of Layer-Structured Photorefractive Composite Containing Nematic Liquid Crystal(E7)-C 60 -PVK (Poly(N-Vinylcarbazole))

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 1999

ABSTRACT

Research paper thumbnail of Second Harmonic Generation and Photorefractive Effect in Dye-Doped Liquid Crystals

Japanese Journal of Applied Physics, 2001

Second harmonic generation (SHG) and photorefractive (PR) effects were observed in a PR cell of l... more Second harmonic generation (SHG) and photorefractive (PR) effects were observed in a PR cell of liquid crystals doped with nonlinear optical (NLO) chromophore. In general, photorefractive materials of liquid crystals have no second harmonic (SH) signals due to the absence of nonlinearity. However, we observed SHG using a Maker Fringes experimental setup and, simultaneously, the asymmetric energy exchange of high

Research paper thumbnail of Mach-Zehnder electro-optic modulator based on organic-silica sol-gel hybrid films

Electronics Letters, 1999

0 IEE 1999 Electronics Letters Online Not19991175 DOI: I0.1049/el:19991175 S. Salvatori, F. Scott... more 0 IEE 1999 Electronics Letters Online Not19991175 DOI: I0.1049/el:19991175 S. Salvatori, F. Scotti, ,G. Conte and MC Rossi (Department of Electronic Engineering and INFM, Universita degli Studi Roma TRE, Via della Vasca Navale 84 - 1146 Rome, Italy)

Research paper thumbnail of Transport and trapping of photocharges in liquid crystals placed between photoconductive polymer layers

Applied Physics Letters, 2001

Research paper thumbnail of Photorefractive behaviors in a polymer composite including layered silicates

Applied Clay Science, 2002

Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is ma... more Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is made up of poly(Nvinylcarbazole) (PVK), 2,4,7-trinitro-9-fluorenone (TNF), 4-(4-nitrophenylazo)aniline (DO3), and 9-ethylcarbazole (ECZ), with or without Montmorillonite (MMT) or laponite as a layered silicate. The structures of nanocomposite-PR samples were investigated by X-ray diffraction (XRD). To investigate the PR property, two-beam coupling (TBC) and four-wave mixing experiments were performed. The gain coefficients of the MMT-based nanocomposite-PR system are somewhat lower than that of the unfilled system. However, the equilibrium normalized final diffracted signal of PR-nanocomposite is higher than the unfilled PR sample. Furthermore, by adding laponite instead of MMT to the polymeric PR system, the gain coefficient increases to the original value of the unfilled system by reducing the light scattering, so that it can be said that the memory stability is greatly enhanced in grating decay behavior.

Research paper thumbnail of Large Two-Beam Coupling Effect In Poly (Methylmethacrylate) Doped With Hemicyanine Dye

Optical Materials, 2003

Electrooptically induced photorefractive effects were first observed in an inorganic crystal, LiN... more Electrooptically induced photorefractive effects were first observed in an inorganic crystal, LiNbO 3 , in 1966 and were interpreted as optical damage [1]. The first photorefractive polymer was reported in 1991 [2]. Photorefractive polymers require four basic ingredients: charge ...

Research paper thumbnail of Procédé et Dispositif D'Extraction De Profondeur Dans Un Appareil Photo À Ouvertures Multiples

Research paper thumbnail of 멀티 애퍼처 카메라에서의 깊이 추출 방법 및 장치

Research paper thumbnail of Optical Fiber With Zero Dispersion Wavelength Shifted to Short Wavelength Region, and Optical Transmission Line and Optical Transmission System Using the Same

Research paper thumbnail of 1933 Transport and trapping of photocharges in liquid crystals placed between photoconductive polymer layers

Research paper thumbnail of Optical fiber, and optical transmission line and optical transmission system using the same

Research paper thumbnail of Photorefractive behaviors in a polymer composite including layered silicates

Applied Clay Science, 2002

Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is ma... more Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is made up of poly(N-vinylcarbazole) (PVK), 2,4,7-trinitro-9-fluorenone (TNF), 4-(4-nitrophenylazo)aniline (DO3), and 9-ethylcarbazole (ECZ), with or without Montmorillonite (MMT) or laponite as a layered silicate. The structures of nanocomposite-PR samples were investigated by X-ray diffraction (XRD). To investigate the PR property, two-beam coupling (TBC) and four-wave mixing experiments were

Research paper thumbnail of Photorefractive effect in nematic liquid crystals doped with nonlinear optical chromophores

LEOS 2001. 14th Annual Meeting of the IEEE Lasers and Electro-Optics Society (Cat. No.01CH37242), 2001

ABSTRACT

Research paper thumbnail of Synthesis and properties of oligomeric poly(glycidyl ether)s with a carbazole-based multifunctional photorefractive chromophore

Reactive and Functional Polymers, 2000

Novel photorefractive poly(glycidyl ether) oligomers of a carbazole-based multifunctional chromop... more Novel photorefractive poly(glycidyl ether) oligomers of a carbazole-based multifunctional chromophore were synthesized via ring-opening cationic polymerization. This new class of materials showed good solubility in various organic solvents and thermal stability up to 4008C. Optical quality films of excellent transparency at the light wavelength above 430 nm were 213 21 22 obtained by spin-coating or casting. Photoconductive sensitivity of the film was as high as 10 S cm / mW cm at 532 21 nm. Electrooptic coefficients (r) of 5-7 pm V were easily achieved by the contact poling of spin-coated films. As 33 21 evidence of photorefractivity, an asymmetric two-beam coupling gain of 3.2 cm was demonstrated at an electric field of 30 21 V mm with a low-T polymer blend of multifunctional poly(glycidyl ether).

Research paper thumbnail of Organometallic−Organic Hybrid Crystals from Ferrocenyl Dipyridine and Binaphthol:  Different Crystal Structures and Nonlinear Optical Properties Depending upon the Reaction Medium and Optical Purity of Binaphthol

Organometallics, 1999

Molecular recognition between 1, 1'-bis (ethenyl-4-pyridyl) ferrocene (1) and (±)-1, 1-b... more Molecular recognition between 1, 1'-bis (ethenyl-4-pyridyl) ferrocene (1) and (±)-1, 1-binaphthol (2)/(-)-1, 1-binaphthol ((-)-2) has been studied by cocrystallization in different solvents. Single-crystal X-ray structures reveal that cocrystallization of 1 and 2/((-)-2 in ...

Research paper thumbnail of Photo-aligned and photo-conductive polymer layers for photorefractive liquid crystal cells of high transmittance

Optical Materials, 2003

The optical performance of photorefractive cells of liquid crystals strongly depends on the align... more The optical performance of photorefractive cells of liquid crystals strongly depends on the alignment of liquid crystals stabilized by surface states. Two photo-aligned polymer layers with relatively weak anchoring energy were investigated by FT-IR and UV/VIS spectroscopies. The cells without alignment layers showed significant scatterings due to random switching under an applied field. The cells with photo-alignment layers showed the

Research paper thumbnail of Layer-Structured Photorefractive Composite Containing Nematic Liquid Crystal(E7)-C 60 -PVK (Poly(N-Vinylcarbazole))

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 1999

ABSTRACT

Research paper thumbnail of Second Harmonic Generation and Photorefractive Effect in Dye-Doped Liquid Crystals

Japanese Journal of Applied Physics, 2001

Second harmonic generation (SHG) and photorefractive (PR) effects were observed in a PR cell of l... more Second harmonic generation (SHG) and photorefractive (PR) effects were observed in a PR cell of liquid crystals doped with nonlinear optical (NLO) chromophore. In general, photorefractive materials of liquid crystals have no second harmonic (SH) signals due to the absence of nonlinearity. However, we observed SHG using a Maker Fringes experimental setup and, simultaneously, the asymmetric energy exchange of high

Research paper thumbnail of Mach-Zehnder electro-optic modulator based on organic-silica sol-gel hybrid films

Electronics Letters, 1999

0 IEE 1999 Electronics Letters Online Not19991175 DOI: I0.1049/el:19991175 S. Salvatori, F. Scott... more 0 IEE 1999 Electronics Letters Online Not19991175 DOI: I0.1049/el:19991175 S. Salvatori, F. Scotti, ,G. Conte and MC Rossi (Department of Electronic Engineering and INFM, Universita degli Studi Roma TRE, Via della Vasca Navale 84 - 1146 Rome, Italy)

Research paper thumbnail of Transport and trapping of photocharges in liquid crystals placed between photoconductive polymer layers

Applied Physics Letters, 2001

Research paper thumbnail of Photorefractive behaviors in a polymer composite including layered silicates

Applied Clay Science, 2002

Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is ma... more Photorefractive (PR) behavior was observed in a polymer nanocomposite system. The composite is made up of poly(Nvinylcarbazole) (PVK), 2,4,7-trinitro-9-fluorenone (TNF), 4-(4-nitrophenylazo)aniline (DO3), and 9-ethylcarbazole (ECZ), with or without Montmorillonite (MMT) or laponite as a layered silicate. The structures of nanocomposite-PR samples were investigated by X-ray diffraction (XRD). To investigate the PR property, two-beam coupling (TBC) and four-wave mixing experiments were performed. The gain coefficients of the MMT-based nanocomposite-PR system are somewhat lower than that of the unfilled system. However, the equilibrium normalized final diffracted signal of PR-nanocomposite is higher than the unfilled PR sample. Furthermore, by adding laponite instead of MMT to the polymeric PR system, the gain coefficient increases to the original value of the unfilled system by reducing the light scattering, so that it can be said that the memory stability is greatly enhanced in grating decay behavior.

Research paper thumbnail of Large Two-Beam Coupling Effect In Poly (Methylmethacrylate) Doped With Hemicyanine Dye

Optical Materials, 2003

Electrooptically induced photorefractive effects were first observed in an inorganic crystal, LiN... more Electrooptically induced photorefractive effects were first observed in an inorganic crystal, LiNbO 3 , in 1966 and were interpreted as optical damage [1]. The first photorefractive polymer was reported in 1991 [2]. Photorefractive polymers require four basic ingredients: charge ...