By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found tha...By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found that the third harmonic susceptibility of polyaniline strongly depends on the delocalization of the electrons. The refractive indices n ( λ =589 nm) of PANI-HCl and PANI-H 3PO 4 are calculated by use of three common methods (the Lorentz-Lorentz theoretical model, the Gladstone-Dale group contribution and the Vogel group correlation) based on group contributions to molar refraction. The calculated n values are varied from 1.31 to 1.42 for PANI-HCl and 1.36 to 1.45 for PANI-H 3PO 4.展开更多
In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computa...In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefrac- rive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. ~, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different ~, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.展开更多
It is shown that bright-dark Manakov solitons can be formed in biased guest-host photorefractive polymer when the total intensity of two components is much lower than the background illumination. The existing conditio...It is shown that bright-dark Manakov solitons can be formed in biased guest-host photorefractive polymer when the total intensity of two components is much lower than the background illumination. The existing conditions of bright-dark Manakov solitons are discussed in detail. The intensity profiles and dynamical evolutions of solitons are presented by numericaJ methods.展开更多
The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200...The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are as- cribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization （TPIP） （8 mW）, is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By ootimizing the laser carvinR oararneters, hizhly efficient grating devices can be fabricated.展开更多
Copolymers of N-pentafluorophenyl maleimide (PFPMI) with methyl methacrylate (MMA) were synthesized by a free radical initiator, such as AIBN. The refractive indexes of the copolymers remained nearly constant (1.4970 ...Copolymers of N-pentafluorophenyl maleimide (PFPMI) with methyl methacrylate (MMA) were synthesized by a free radical initiator, such as AIBN. The refractive indexes of the copolymers remained nearly constant (1.4970 at 532 nm) regardless of the polymer composition. These copolymers also showed high thermal stability. The orientational and photoelastic birefringence of the copolymers obtained were measured. Since both of the orientational and photoelastic birefringences of PMMA are negative whereas poly(PFPMI) exhibits positive, thus we have obtained nearly zero orientational and photoelastic birefringence polymers when the ratios of MMA/PFPMI were 91.8/8.2 and 97.0/3.0 mol%, respectively. Based on the experimental data, the ratios of MMA/PFPMI for zero birefringence were determined to be 88.9/11.1 and 93.8/6.2 mol% for orientational and photoelastic birefringence, respectively. The Tgs of corresponding copolymers were estimated to be 128 and 122 ℃.展开更多
文摘By use of the Keldysh non-equilibrium Green’s-function methods, the third harmonic susceptibilities of two polyaniline families, PANI-HCl and PANI-H 3PO 4, are calculated [ x (3) ( ω )≈10 -12 esu]. It was found that the third harmonic susceptibility of polyaniline strongly depends on the delocalization of the electrons. The refractive indices n ( λ =589 nm) of PANI-HCl and PANI-H 3PO 4 are calculated by use of three common methods (the Lorentz-Lorentz theoretical model, the Gladstone-Dale group contribution and the Vogel group correlation) based on group contributions to molar refraction. The calculated n values are varied from 1.31 to 1.42 for PANI-HCl and 1.36 to 1.45 for PANI-H 3PO 4.
基金Supported by the National Natural Science Foundation of China under Grant No.11272023the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)Supported by the Fundamental Research Funds for the Central Universities of China under Grant No.2011BUPTYB02
文摘In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefrac- rive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. ~, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different ~, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.
基金Supported by the Natural Science Foundation of Shanxi Province under Grant No. 2011011003-2the Science and Technology Development Foundation of Higher Education of Shanxi Province under Grant No. 20111125
文摘It is shown that bright-dark Manakov solitons can be formed in biased guest-host photorefractive polymer when the total intensity of two components is much lower than the background illumination. The existing conditions of bright-dark Manakov solitons are discussed in detail. The intensity profiles and dynamical evolutions of solitons are presented by numericaJ methods.
基金supported by the National Natural Science Foundation of China/the Research Grants Council of Hong Kong Joint Research Scheme a grant for NSFC/RGC(No.50218001)the National Science Foundation of China(No.50173015)
文摘The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are as- cribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization （TPIP） （8 mW）, is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By ootimizing the laser carvinR oararneters, hizhly efficient grating devices can be fabricated.
基金supported by the Japan Society for the Promotion of Science (JSPS) through its "Funding Program for World Leading Innovative R&D on Science and Technology (FIRST Program)"
文摘Copolymers of N-pentafluorophenyl maleimide (PFPMI) with methyl methacrylate (MMA) were synthesized by a free radical initiator, such as AIBN. The refractive indexes of the copolymers remained nearly constant (1.4970 at 532 nm) regardless of the polymer composition. These copolymers also showed high thermal stability. The orientational and photoelastic birefringence of the copolymers obtained were measured. Since both of the orientational and photoelastic birefringences of PMMA are negative whereas poly(PFPMI) exhibits positive, thus we have obtained nearly zero orientational and photoelastic birefringence polymers when the ratios of MMA/PFPMI were 91.8/8.2 and 97.0/3.0 mol%, respectively. Based on the experimental data, the ratios of MMA/PFPMI for zero birefringence were determined to be 88.9/11.1 and 93.8/6.2 mol% for orientational and photoelastic birefringence, respectively. The Tgs of corresponding copolymers were estimated to be 128 and 122 ℃.
