The Experts below are selected from a list of 387 Experts worldwide ranked by ideXlab platform
Qiwei Pan - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear optical properties and thermal stability of the poled polymer NTAB/PEK-c
Materials Letters, 2002Co-Authors: Qiwei Pan, Changshui Fang, Zhihui Qin, Xiufeng ChengAbstract:Films of high glass' transition temperature polymer polyetherketone doped with chromophore 2,2'[4-[(5-nitro-2-thiazolyl)azophenyl]-amino]-bisethanol NTAB) were prepared, poled by the corona-onset poling setup which includes a grid voltage making the surface-charge distribution uniform at elevated temperature. The thickness of the films was measured by the Model 2010 Prism Coupler system. Second harmonic generation d(33) was measured by the second harmonic generation method, and the d33 is 38.12 pm/V at 1064 nm under the absorption correction. The nonlinear optical activity maintains is 80% of its initial value. (C) 2002 Elsevier Science B.V. All rights reserved.
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Guest–host polyetherketone polymer for applications in integrated-optical devices: characterization
Journal of the Optical Society of America B, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Thin films of polyetherketone guest–host polymer doped with 3-(1,1-dicyanothenyl)-1-phenyl-4, 5-dihydro-1H-pryazole were prepared. Linear electro-optic coefficients of poled-polymer films have been determined at λ=632.8 nm by use of a simple interferometric technique. Temporal and temperature stability of the poled-polymer film was measured by probing linear electro-optic activity and second-harmonic signal intensity, respectively. For the poled-polymer films the lower-order optical waveguide-transmission losses were measured at 632.8 nm. The measurements showed that the optical loss of the fundamental mode was less than 0.5 dB cm-1 for transverse electric-field polarization.
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Single-mode rib polymer waveguides and electro-optic polymer waveguide switches
Optics and Lasers in Engineering, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Abstract Mode-matching and effective index methods are used to analyze single-mode operation of optical rib polymer waveguides. Their single-mode waveguiding conditions are determined. Single-mode rib waveguides fabricated from guest–host polyetherketone are presented. The estimated propagation loss of straight rib-waveguides is 0.7 dB/cm at 1.55 μm. Furthermore, by using the mode field-transfer matrix method, 2×2 and 4×4 polymer Mach–Zehnder interference switch operating at 1.55 μm wavelength has been designed based on optical multi-mode interference.
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Investigation of the new guest-host polyetherketone poled polymer
Journal of Materials Science Letters, 2001Co-Authors: Qiwei Pan, Wei Shi, Changshui FangAbstract:shandong univ, inst crystal mat, state key lab, jinan 250100, peoples r china; acad sinica, inst semicond, beijing 100083, peoples r china
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Investigation of the linear electro-optic effect for the guest-host polymer DR13/PEK-c thin films
Optics and Lasers in Engineering, 2001Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Xin Yin, Hongzhen WeiAbstract:Abstract The polyetherketone (PEK-c) guest–host polymer thin films doped with disperse red 13 were prepared by spin-coating method. The corona poling condition was optimized by the poling profiles. The polymer films were poled by corona-onset poling at elevated temperature, and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. The linear electro-optic coefficients of the poled polymer films have been determined at λ=632.8 nm by using a new simple interferometric technique, which is based on compensating the change of the optical length due to the electro-optic effect of the poled polymer film by the anti-piezoelectric effect of a quartz crystal.
Wei Shi - One of the best experts on this subject based on the ideXlab platform.
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Guest–host polyetherketone polymer for applications in integrated-optical devices: characterization
Journal of the Optical Society of America B, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Thin films of polyetherketone guest–host polymer doped with 3-(1,1-dicyanothenyl)-1-phenyl-4, 5-dihydro-1H-pryazole were prepared. Linear electro-optic coefficients of poled-polymer films have been determined at λ=632.8 nm by use of a simple interferometric technique. Temporal and temperature stability of the poled-polymer film was measured by probing linear electro-optic activity and second-harmonic signal intensity, respectively. For the poled-polymer films the lower-order optical waveguide-transmission losses were measured at 632.8 nm. The measurements showed that the optical loss of the fundamental mode was less than 0.5 dB cm-1 for transverse electric-field polarization.
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Single-mode rib polymer waveguides and electro-optic polymer waveguide switches
Optics and Lasers in Engineering, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Abstract Mode-matching and effective index methods are used to analyze single-mode operation of optical rib polymer waveguides. Their single-mode waveguiding conditions are determined. Single-mode rib waveguides fabricated from guest–host polyetherketone are presented. The estimated propagation loss of straight rib-waveguides is 0.7 dB/cm at 1.55 μm. Furthermore, by using the mode field-transfer matrix method, 2×2 and 4×4 polymer Mach–Zehnder interference switch operating at 1.55 μm wavelength has been designed based on optical multi-mode interference.
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Investigation of the new guest-host polyetherketone poled polymer
Journal of Materials Science Letters, 2001Co-Authors: Qiwei Pan, Wei Shi, Changshui FangAbstract:shandong univ, inst crystal mat, state key lab, jinan 250100, peoples r china; acad sinica, inst semicond, beijing 100083, peoples r china
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Investigation of the linear electro-optic effect for the guest-host polymer DR13/PEK-c thin films
Optics and Lasers in Engineering, 2001Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Xin Yin, Hongzhen WeiAbstract:Abstract The polyetherketone (PEK-c) guest–host polymer thin films doped with disperse red 13 were prepared by spin-coating method. The corona poling condition was optimized by the poling profiles. The polymer films were poled by corona-onset poling at elevated temperature, and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. The linear electro-optic coefficients of the poled polymer films have been determined at λ=632.8 nm by using a new simple interferometric technique, which is based on compensating the change of the optical length due to the electro-optic effect of the poled polymer film by the anti-piezoelectric effect of a quartz crystal.
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Investigation of a new electro-optical guest–host polyetherketone polymer films
Optics and Lasers in Engineering, 2001Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Hongzhen Wei, Xiaofeng ZhangAbstract:Abstract The polyetherketone (PEK-c) guest–host system thin films in which the range of the weight percent of 3-(1,1-dicyanothenyl)-1-phenyl-4, 5-dihydro-1H-pyrazole (DCNP) is from 20% to 50% were prepared. Their corona poling temperatures were optimized by using the in situ second-harmonic generation (SHG) measurement. The high predicted value of electro-optical (EO) coefficient γ 33 =48.8 pm/v by using two-level model was obtained when the weight percent of DCNP in the polymer system is 40%, but EO coefficients are attenuated at higher chromophore loading than 40%. The temporal stability of the EO activity of the guest–host polymer was evaluated by probing the decay of the orientational order of the chromophores in the polymer system.
Changshui Fang - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear optical properties and thermal stability of the poled polymer NTAB/PEK-c
Materials Letters, 2002Co-Authors: Qiwei Pan, Changshui Fang, Zhihui Qin, Xiufeng ChengAbstract:Films of high glass' transition temperature polymer polyetherketone doped with chromophore 2,2'[4-[(5-nitro-2-thiazolyl)azophenyl]-amino]-bisethanol NTAB) were prepared, poled by the corona-onset poling setup which includes a grid voltage making the surface-charge distribution uniform at elevated temperature. The thickness of the films was measured by the Model 2010 Prism Coupler system. Second harmonic generation d(33) was measured by the second harmonic generation method, and the d33 is 38.12 pm/V at 1064 nm under the absorption correction. The nonlinear optical activity maintains is 80% of its initial value. (C) 2002 Elsevier Science B.V. All rights reserved.
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Guest–host polyetherketone polymer for applications in integrated-optical devices: characterization
Journal of the Optical Society of America B, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Thin films of polyetherketone guest–host polymer doped with 3-(1,1-dicyanothenyl)-1-phenyl-4, 5-dihydro-1H-pryazole were prepared. Linear electro-optic coefficients of poled-polymer films have been determined at λ=632.8 nm by use of a simple interferometric technique. Temporal and temperature stability of the poled-polymer film was measured by probing linear electro-optic activity and second-harmonic signal intensity, respectively. For the poled-polymer films the lower-order optical waveguide-transmission losses were measured at 632.8 nm. The measurements showed that the optical loss of the fundamental mode was less than 0.5 dB cm-1 for transverse electric-field polarization.
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Single-mode rib polymer waveguides and electro-optic polymer waveguide switches
Optics and Lasers in Engineering, 2002Co-Authors: Wei Shi, Changshui Fang, Yujie J. Ding, Qiwei PanAbstract:Abstract Mode-matching and effective index methods are used to analyze single-mode operation of optical rib polymer waveguides. Their single-mode waveguiding conditions are determined. Single-mode rib waveguides fabricated from guest–host polyetherketone are presented. The estimated propagation loss of straight rib-waveguides is 0.7 dB/cm at 1.55 μm. Furthermore, by using the mode field-transfer matrix method, 2×2 and 4×4 polymer Mach–Zehnder interference switch operating at 1.55 μm wavelength has been designed based on optical multi-mode interference.
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Investigation of the new guest-host polyetherketone poled polymer
Journal of Materials Science Letters, 2001Co-Authors: Qiwei Pan, Wei Shi, Changshui FangAbstract:shandong univ, inst crystal mat, state key lab, jinan 250100, peoples r china; acad sinica, inst semicond, beijing 100083, peoples r china
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Investigation of the linear electro-optic effect for the guest-host polymer DR13/PEK-c thin films
Optics and Lasers in Engineering, 2001Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Xin Yin, Hongzhen WeiAbstract:Abstract The polyetherketone (PEK-c) guest–host polymer thin films doped with disperse red 13 were prepared by spin-coating method. The corona poling condition was optimized by the poling profiles. The polymer films were poled by corona-onset poling at elevated temperature, and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. The linear electro-optic coefficients of the poled polymer films have been determined at λ=632.8 nm by using a new simple interferometric technique, which is based on compensating the change of the optical length due to the electro-optic effect of the poled polymer film by the anti-piezoelectric effect of a quartz crystal.
Hongzheng Wei - One of the best experts on this subject based on the ideXlab platform.
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Determination of the macroscopic optical properties for the NAEC/PEK-c guest–host polymer films
Optics and Lasers in Engineering, 2001Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Hongzheng WeiAbstract:The polyetherketone (PEK-c) guest-host polymer films doped with (4'-nitro)-3-azo-9-ethyl-carbazole (NAEC) were prepared. The films were poled by corona-onset poling at elevated temperature (COPET). The orientational order parameter of the chromophores NAEC in poled polymer film was determined by measuring the absorption spectra of the films before and after being poled. By using the two-level model, the measured dispersion of the refractive index of the polymer film, and the dispersion of the first hyperpolarizability of chromophore NAEC, the dispersion of the macroscopic second-order nonlinear optical (NLO) and linear electrooptic (EO) coefficients was evaluated for the NAEC/PEK-c guest-host polymer film. (C) 2001 Elsevier Science Ltd. All rights reserved.
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Poling optimization and optical loss measurement of the polyetherketone polymer films
Solid State Communications, 2000Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Hongzheng WeiAbstract:Abstract Polyetherketone (PEK-c) guest–host polymer thin films doped with 3-(1,1-dicyanothenyl)-1-phenyl1-4,5-dihydro-1H-pryazole were prepared. Through in situ second-harmonic generation (SHG), the corona poling temperature was optimized by measuring the temperature dependence of the in situ SHG signal intensity under the poling electric field. The second-order NLO coefficient χ 33 (2) =16.67 pm/V at λ=1064 nm was determined by using the Maker fringe method after poling condition. For the poled polymer films, the lower-order optical waveguide-transmission losses were measured at 632.8 nm. The measurements showed that the optical loss of the fundamental mode is less than 0.5 dB cm−1 for TE polarization.
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Measurement of the optical transmission modes and losses of the poled guest–host polymer NAEC/PEK-c planar waveguides
Optics and Lasers in Engineering, 2000Co-Authors: Wei Shi, Qiwei Pan, Changshui Fang, Hongzheng WeiAbstract:The polyetherketone (PEK-c) guest-host polymer planar waveguides doped with (4'-nitro)-3-azo-9-ethyl-carbazole (NAEC) were prepared. The waveguide films were poled by corona-onset poling at elevated temperature (COPET), and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. By using the prism-in coupling method, the dark-line spectrum given by the reflected intensity versus the angle of incidence have been obtained, and the optical transmission losses of mth modes have been measured for the poled polymer waveguides at lambda = 632.8 nm. The measurement result showed that the optical loss of the fundamental mode is less than 0.7 dB cm(-1) for the TE polarization. (C) 2000 Elsevier Science Ltd. All rights reserved.
Carola Kolbeck - One of the best experts on this subject based on the ideXlab platform.
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Shear bond strength between veneering composite and PEEK after different surface modifications
Clinical Oral Investigations, 2015Co-Authors: Martin Rosentritt, Verena Preis, Michael Behr, Nuno Sereno, Carola KolbeckAbstract:Objectives This study aims to test the influence of different surface treatments and conditioning on the shear bond strength between polyetherketone (PEEK) and composite. Materials and methods Surfaces (570 plates) were used untreated, etched, air-particle abraded or activated with silica-modified alumina oxide. Surface roughness was determined after different treatments. Cylinders of composite were polymerized onto the surfaces. Eighteen different pre-treatment combinations were applied, partly combined with opaque application. Shear bond strength (SBS) was determined following ISO TR 11405. Baseline tests were performed 24 h after composite polymerization. For investigating the influence of storage and aging, the specimens were either stored in distilled water (37 °C, 90 days) or thermally cycled (12,000 cycles 5 °C/55 °C, distilled water). Means and standard deviations were calculated (statistics: one-way ANOVA/Bonferroni (α = 0.05)). Results Surface roughness varied between 0.04 ± 0.01 and 6.76 ± 1.11 μm. Only etching caused a significant ( p
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Shear bond strength between veneering composite and PEEK after different surface modifications.
Clinical oral investigations, 2014Co-Authors: Martin Rosentritt, Verena Preis, Michael Behr, Nuno Sereno, Carola KolbeckAbstract:Objectives This study aims to test the influence of different surface treatments and conditioning on the shear bond strength between polyetherketone (PEEK) and composite.