Haiping YU - Academia.edu (original) (raw)
Papers by Haiping YU
Emerging Liquid Crystal Technologies XII
Journal of the Chemical Society, Faraday Transactions, 1992
The laser-induced fluorescence spectra of jet-cooled N-(4-cyanophenyl)carbazole (CPC) and its (1 ... more The laser-induced fluorescence spectra of jet-cooled N-(4-cyanophenyl)carbazole (CPC) and its (1 : 1) complexes with various partner species Ar, C6H6, C6H12, CH3OH, CHCI3, CH3CN are presented. With CCI4, no fluorescent complex was observed. The other 1 : 1 complexes observed gave rise to red-shifted features, which indicates a stabilisation of the S1 state of the complex relative to its ground state. Inductive and dispersive forces thus play an important role in both non-polar and solvents with small dipole moment and large polarisability. The dipole–dipole interactions involve the dipoles of the polar solvent and CPC in an anti-parallel arrangement. With the exception of CPC–Ar2, no complexes of higher than 1 : 1 stoichiometry were observed. An attempt was made to produce in the jet the characteristic red-shifted broad emission from the so-called twisted intramolecular charge transfer (TICT) states seen in polar solution. No such emission was observed.
Journal of the Chemical Society, Faraday Transactions, 1993
ABSTRACT
The Journal of Physical Chemistry, 1993
I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spe... more I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spectroscopy and dynamics of substituted benzene derivatives, including 1 ,Cdifluorobenzene, 1,2 4-fl~orotoluene,3.~ aniline,- substituted alkylben ~ enes , ~ ~ ~ benzonitrile,l6 and me- ...
Physica Scripta, 1991
... One of the reasons for the extensive interest in carbon clusters is the observation by Smalle... more ... One of the reasons for the extensive interest in carbon clusters is the observation by Smalley, Kroto ... Also there is no way to determine the Coulomb explosion limit for k = 2 since odd singly ... Assuming that large clusters consist of carbon shells, their total energy can be written as E ...
Optics Express, 2005
External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials ... more External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials with electrically tunable stop band is reported. The tunable PBG materials are developed from a family of novel cholesteric liquid crystals (CLC) with electrically variable pitch that adopts a non-constant distribution in space across the CLC film. The CLC exhibits a distributed feedback cavity whose resonant frequency can be electrically varied over a spectral range wider than 300 nm. Under an optical pumping and subject to a variable electric field, a tunable laser has been demonstrated in experiment that shows a wavelength tuning over 33 nm.
Journal of the American Chemical Society, 2004
Photo-optic materials offer the possibility of light controlled photonic devices, intelligent and... more Photo-optic materials offer the possibility of light controlled photonic devices, intelligent and environmentally adaptive optical materials. One strategy for creating these materials is the combination of structure formation through holographic photopolymerization and the variable optical properties of liquid crystals. Holographically patterned, polymer stabilized liquid crystals (HPSLCs) have proven to be useful optical materials. By incorporating photo-optic, azobenzene-derived liquid crystal blends into such material systems, we have generated practical photoresponsive optical materials.
Journal of Photochemistry and Photobiology A: Chemistry, 1994
Laser-induced fluorescence (LIF) spectra of jet-cooled carbazale, N-ethylcarbazole (EC), N-phenyl... more Laser-induced fluorescence (LIF) spectra of jet-cooled carbazale, N-ethylcarbazole (EC), N-phenylcarbazole (PC), N-(4cyanophenyl)carbazole (CPC) and N-anthrylcarbazole (AC) are presented and analysed. Perpendicularity is proposed in the ground state geometry of PC and CPC, in contrast with the twisted angle in AC, and these ground state configurations of PC and CPC are preserved on electronic excitation, but not in AC. The electron distribution on the nitrogen atom in the carbazole moiety is used as a basis to explain the differences in the spectral shifts of the substituted carbazoles with respect to the bare carbazole chromophore. PC complexes with argon atoms, non-Polar and polar molecules were investigated and compared with those of CPC and EC. Intermolecular vibrational modes were observed in several PC complexes. The similarity of the spectra1 shifts of PC complexes to those of CPC indicates that they have very similar properties under jet conditions, in contrast with observations in acetonitrile solution. No twisted intramolecular charge transfer (TICT) took place for PC and CPC, where the perpendicularity is preserved on electronic excitation, which is in agreement with the fact that TICT fluorescence emission was not observed in the jet for CPC-acetonitrile complexes.
The Journal of Chemical Physics, 1997
ABSTRACT
Chemical Physics Letters, 1993
Chemical Physics Letters, 1993
ABSTRACT
Optics Express, 2005
External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials ... more External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials with electrically tunable stop band is reported. The tunable PBG materials are developed from a family of novel cholesteric liquid crystals (CLC) with electrically variable pitch that ...
Chemical Physics Letters, 1993
ABSTRACT
This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the... more This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the short wave infrared (SWIR) regime, can be used for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. The MPSP system generates both static and video images (up to 200 Hz) with 512×512 spatial resolution with active spatial, spectral, and polarization modulation with controlled bandwidth. It projects input
Applied Physics Letters, 1995
Growth of high quality As/GaAs quantum wells (QWs) is crucial to the fabrication of strained laye... more Growth of high quality As/GaAs quantum wells (QWs) is crucial to the fabrication of strained layer lasers as pump sources for Er-doped fiber amplifiers and modulators operating in the 920980 nm region. For these applications, the In fraction, x, must be less than 0.25; otherwise, ...
The Journal of …, 1993
I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spe... more I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spectroscopy and dynamics of substituted benzene derivatives, including 1 ,Cdifluorobenzene, 1,2 4-fl~orotoluene,3.~ aniline,- substituted alkylben ~ enes , ~ ~ ~ benzonitrile,l6 and me- ...
Applied Physics Letters, 1996
We have investigated the exciton kinetics in self‐assembled InAs quantum dots and ultrathin quant... more We have investigated the exciton kinetics in self‐assembled InAs quantum dots and ultrathin quantum wells grown by molecular beam epitaxy on (001) oriented GaAs substrates. At low temperatures, the photoluminescence decay time of the quantum wells increases almost ...
Emerging Liquid Crystal Technologies XII
Journal of the Chemical Society, Faraday Transactions, 1992
The laser-induced fluorescence spectra of jet-cooled N-(4-cyanophenyl)carbazole (CPC) and its (1 ... more The laser-induced fluorescence spectra of jet-cooled N-(4-cyanophenyl)carbazole (CPC) and its (1 : 1) complexes with various partner species Ar, C6H6, C6H12, CH3OH, CHCI3, CH3CN are presented. With CCI4, no fluorescent complex was observed. The other 1 : 1 complexes observed gave rise to red-shifted features, which indicates a stabilisation of the S1 state of the complex relative to its ground state. Inductive and dispersive forces thus play an important role in both non-polar and solvents with small dipole moment and large polarisability. The dipole–dipole interactions involve the dipoles of the polar solvent and CPC in an anti-parallel arrangement. With the exception of CPC–Ar2, no complexes of higher than 1 : 1 stoichiometry were observed. An attempt was made to produce in the jet the characteristic red-shifted broad emission from the so-called twisted intramolecular charge transfer (TICT) states seen in polar solution. No such emission was observed.
Journal of the Chemical Society, Faraday Transactions, 1993
ABSTRACT
The Journal of Physical Chemistry, 1993
I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spe... more I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spectroscopy and dynamics of substituted benzene derivatives, including 1 ,Cdifluorobenzene, 1,2 4-fl~orotoluene,3.~ aniline,- substituted alkylben ~ enes , ~ ~ ~ benzonitrile,l6 and me- ...
Physica Scripta, 1991
... One of the reasons for the extensive interest in carbon clusters is the observation by Smalle... more ... One of the reasons for the extensive interest in carbon clusters is the observation by Smalley, Kroto ... Also there is no way to determine the Coulomb explosion limit for k = 2 since odd singly ... Assuming that large clusters consist of carbon shells, their total energy can be written as E ...
Optics Express, 2005
External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials ... more External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials with electrically tunable stop band is reported. The tunable PBG materials are developed from a family of novel cholesteric liquid crystals (CLC) with electrically variable pitch that adopts a non-constant distribution in space across the CLC film. The CLC exhibits a distributed feedback cavity whose resonant frequency can be electrically varied over a spectral range wider than 300 nm. Under an optical pumping and subject to a variable electric field, a tunable laser has been demonstrated in experiment that shows a wavelength tuning over 33 nm.
Journal of the American Chemical Society, 2004
Photo-optic materials offer the possibility of light controlled photonic devices, intelligent and... more Photo-optic materials offer the possibility of light controlled photonic devices, intelligent and environmentally adaptive optical materials. One strategy for creating these materials is the combination of structure formation through holographic photopolymerization and the variable optical properties of liquid crystals. Holographically patterned, polymer stabilized liquid crystals (HPSLCs) have proven to be useful optical materials. By incorporating photo-optic, azobenzene-derived liquid crystal blends into such material systems, we have generated practical photoresponsive optical materials.
Journal of Photochemistry and Photobiology A: Chemistry, 1994
Laser-induced fluorescence (LIF) spectra of jet-cooled carbazale, N-ethylcarbazole (EC), N-phenyl... more Laser-induced fluorescence (LIF) spectra of jet-cooled carbazale, N-ethylcarbazole (EC), N-phenylcarbazole (PC), N-(4cyanophenyl)carbazole (CPC) and N-anthrylcarbazole (AC) are presented and analysed. Perpendicularity is proposed in the ground state geometry of PC and CPC, in contrast with the twisted angle in AC, and these ground state configurations of PC and CPC are preserved on electronic excitation, but not in AC. The electron distribution on the nitrogen atom in the carbazole moiety is used as a basis to explain the differences in the spectral shifts of the substituted carbazoles with respect to the bare carbazole chromophore. PC complexes with argon atoms, non-Polar and polar molecules were investigated and compared with those of CPC and EC. Intermolecular vibrational modes were observed in several PC complexes. The similarity of the spectra1 shifts of PC complexes to those of CPC indicates that they have very similar properties under jet conditions, in contrast with observations in acetonitrile solution. No twisted intramolecular charge transfer (TICT) took place for PC and CPC, where the perpendicularity is preserved on electronic excitation, which is in agreement with the fact that TICT fluorescence emission was not observed in the jet for CPC-acetonitrile complexes.
The Journal of Chemical Physics, 1997
ABSTRACT
Chemical Physics Letters, 1993
Chemical Physics Letters, 1993
ABSTRACT
Optics Express, 2005
External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials ... more External cavity-free and electrically tunable laser made from photonics band gap (PBG) materials with electrically tunable stop band is reported. The tunable PBG materials are developed from a family of novel cholesteric liquid crystals (CLC) with electrically variable pitch that ...
Chemical Physics Letters, 1993
ABSTRACT
This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the... more This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the short wave infrared (SWIR) regime, can be used for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. The MPSP system generates both static and video images (up to 200 Hz) with 512×512 spatial resolution with active spatial, spectral, and polarization modulation with controlled bandwidth. It projects input
Applied Physics Letters, 1995
Growth of high quality As/GaAs quantum wells (QWs) is crucial to the fabrication of strained laye... more Growth of high quality As/GaAs quantum wells (QWs) is crucial to the fabrication of strained layer lasers as pump sources for Er-doped fiber amplifiers and modulators operating in the 920980 nm region. For these applications, the In fraction, x, must be less than 0.25; otherwise, ...
The Journal of …, 1993
I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spe... more I. Introduction A great deal of effort has been applied to the understanding of the gas-phase spectroscopy and dynamics of substituted benzene derivatives, including 1 ,Cdifluorobenzene, 1,2 4-fl~orotoluene,3.~ aniline,- substituted alkylben ~ enes , ~ ~ ~ benzonitrile,l6 and me- ...
Applied Physics Letters, 1996
We have investigated the exciton kinetics in self‐assembled InAs quantum dots and ultrathin quant... more We have investigated the exciton kinetics in self‐assembled InAs quantum dots and ultrathin quantum wells grown by molecular beam epitaxy on (001) oriented GaAs substrates. At low temperatures, the photoluminescence decay time of the quantum wells increases almost ...