Di Liang - Academia.edu (original) (raw)
Papers by Di Liang
Journal of Applied Polymer Science, 2007
Chitosan fibers were treated with aqueous solutions of ZnCl2 and CuSO4·5H2O to prepare zinc and c... more Chitosan fibers were treated with aqueous solutions of ZnCl2 and CuSO4·5H2O to prepare zinc and copper containing fibers, respectively. Significant weight gains were obtained as the zinc and copper ions were absorbed onto the fibers through chelation with the primary amine groups. The fibers were then placed in contact with aqueous solutions containing NaCl and water soluble proteins, respectively, to assess the release of zinc and copper ions. Results showed that the release of zinc and copper ions were affected by the treatment temperature, time, and the composition of the contacting media. More metal ions were released when the fibers were in contact with aqueous protein solutions than in NaCl solution, indicating the binding abilities of the protein molecules for zinc and copper ions. The zinc and copper containing fibers were tested for their antimicrobial effects against several species of bacteria commonly found in wound and skin. Results showed that these metal containing chitosan fibers had much stronger antimicrobial properties than the original chitosan fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Chinese Journal of Aeronautics, 2005
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
IEEE Photonics Technology Letters, 2007
IEEE Photonics Technology Letters, 2007
IEEE Journal of Selected Topics in Quantum Electronics, 2007
Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveg... more Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveguides in AlGaAs heterostructures containing lambda = 808 nm InAlGaAs single quantum well or aluminum-free lambda = 1.3 mum GaAsP/InGaAsN dilute nitride multi-quantum-well active regions have been directly oxidized to effectively provide simultaneous electrical isolation, interface state passivation, and sidewall roughness reduction. The resulting high- index-contrast (HIC) ridge waveguide
IEEE Journal of Selected Topics in Quantum Electronics, 2007
Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveg... more Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveguides in AlGaAs heterostructures containing lambda = 808 nm InAlGaAs single quantum well or aluminum-free lambda = 1.3 mum GaAsP/InGaAsN dilute nitride multi-quantum-well active regions have been directly oxidized to effectively provide simultaneous electrical isolation, interface state passivation, and sidewall roughness reduction. The resulting high- index-contrast (HIC) ridge waveguide
A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which... more A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which enables high-index-contrast (HIC) ridge waveguide (RWG) lasers fabricated in a high-efficiency, high-power AlGaAs/InAlGaAs/GaAs graded-index separate confinement heterostructure to operate with a curved half-ring resonator geometry having a bend radius as low as 10 μm. A wet thermal oxidation process modified through addition of <1% O II to the N 2 carrier gas is shown to smooth the sidewall roughness of etched AlGaAs ridge structures 10-100 fold as the oxidation front progresses inward. The reduction of propagation scattering loss due to the reduced sidewall roughness is examined. The thermal oxide grown on the deeply-etched RWG sidewalls and base also provides electrical isolation from the contact metallization, resulting in a simplified, self-aligned process, and yields a RWG structure which effectively prevents current spreading. The thermal oxide appears to be of sufficiently high quality to passivate the etched active region surface based on a comparative analysis of straight RWG lasers of varying stripe widths (w=5 to 150 μm) passivated with native-oxide vs. PECVD-deposited SiO II. For example, at w<15 μm, the SiO II-insulated devices have ~2X higher threshold current densities than the native-oxide devices for comparable bar lengths. The resulting high lateral optical confinement factor at the semiconductor/oxide interface (Δn=1.69) significantly enhances the laser gain and efficiency. A native-oxide-defined straight laser (w=7 μm, L= 452 μm) operates cw (300 K, unbonded, p-side up) with a threshold current of I th=21.5 mA (J th=679.5 A/cm2) and slope efficiency of 1.19 A/W (differential quantum efficiency = 78%) at a wavelength of ~813 nm.
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which... more A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which enables high-index-contrast (HIC) ridge waveguide (RWG) lasers fabricated in a high-efficiency, high-power AlGaAs/InAlGaAs/GaAs graded-index separate confinement heterostructure to operate with a curved half-ring resonator geometry having a bend radius as low as 10 μm. A wet thermal oxidation process modified through addition of <1% O II to the N 2 carrier gas is shown to smooth the sidewall roughness of etched AlGaAs ridge structures 10-100 fold as the oxidation front progresses inward. The reduction of propagation scattering loss due to the reduced sidewall roughness is examined. The thermal oxide grown on the deeply-etched RWG sidewalls and base also provides electrical isolation from the contact metallization, resulting in a simplified, self-aligned process, and yields a RWG structure which effectively prevents current spreading. The thermal oxide appears to be of sufficiently high quality to passivate the etched active region surface based on a comparative analysis of straight RWG lasers of varying stripe widths (w=5 to 150 μm) passivated with native-oxide vs. PECVD-deposited SiO II. For example, at w<15 μm, the SiO II-insulated devices have ~2X higher threshold current densities than the native-oxide devices for comparable bar lengths. The resulting high lateral optical confinement factor at the semiconductor/oxide interface (Δn=1.69) significantly enhances the laser gain and efficiency. A native-oxide-defined straight laser (w=7 μm, L= 452 μm) operates cw (300 K, unbonded, p-side up) with a threshold current of I th=21.5 mA (J th=679.5 A/cm2) and slope efficiency of 1.19 A/W (differential quantum efficiency = 78%) at a wavelength of ~813 nm.
A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated u... more A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated using a wet thermal oxidation process modified through addition of <1% O2 to the N2 carrier gas, potentially enabling high index contrast waveguides with ultra-low scattering loss for ring resonator and other photonics device applications
IEEE Photonics Technology Letters, 2007
A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated u... more A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated using a wet thermal oxidation process modified through addition of <1% O2 to the N2 carrier gas, potentially enabling high index contrast waveguides with ultra-low scattering loss for ring resonator and other photonics device applications
Journal of Applied Polymer Science, 2007
Chitosan fibers were treated with aqueous solutions of ZnCl2 and CuSO4·5H2O to prepare zinc and c... more Chitosan fibers were treated with aqueous solutions of ZnCl2 and CuSO4·5H2O to prepare zinc and copper containing fibers, respectively. Significant weight gains were obtained as the zinc and copper ions were absorbed onto the fibers through chelation with the primary amine groups. The fibers were then placed in contact with aqueous solutions containing NaCl and water soluble proteins, respectively, to assess the release of zinc and copper ions. Results showed that the release of zinc and copper ions were affected by the treatment temperature, time, and the composition of the contacting media. More metal ions were released when the fibers were in contact with aqueous protein solutions than in NaCl solution, indicating the binding abilities of the protein molecules for zinc and copper ions. The zinc and copper containing fibers were tested for their antimicrobial effects against several species of bacteria commonly found in wound and skin. Results showed that these metal containing chitosan fibers had much stronger antimicrobial properties than the original chitosan fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Chinese Journal of Aeronautics, 2005
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
IEEE Photonics Technology Letters, 2007
IEEE Photonics Technology Letters, 2007
IEEE Journal of Selected Topics in Quantum Electronics, 2007
Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveg... more Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveguides in AlGaAs heterostructures containing lambda = 808 nm InAlGaAs single quantum well or aluminum-free lambda = 1.3 mum GaAsP/InGaAsN dilute nitride multi-quantum-well active regions have been directly oxidized to effectively provide simultaneous electrical isolation, interface state passivation, and sidewall roughness reduction. The resulting high- index-contrast (HIC) ridge waveguide
IEEE Journal of Selected Topics in Quantum Electronics, 2007
Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveg... more Using a modified, O2-enhanced nonselective wet thermal oxidation process, deep-etched ridge waveguides in AlGaAs heterostructures containing lambda = 808 nm InAlGaAs single quantum well or aluminum-free lambda = 1.3 mum GaAsP/InGaAsN dilute nitride multi-quantum-well active regions have been directly oxidized to effectively provide simultaneous electrical isolation, interface state passivation, and sidewall roughness reduction. The resulting high- index-contrast (HIC) ridge waveguide
A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which... more A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which enables high-index-contrast (HIC) ridge waveguide (RWG) lasers fabricated in a high-efficiency, high-power AlGaAs/InAlGaAs/GaAs graded-index separate confinement heterostructure to operate with a curved half-ring resonator geometry having a bend radius as low as 10 μm. A wet thermal oxidation process modified through addition of <1% O II to the N 2 carrier gas is shown to smooth the sidewall roughness of etched AlGaAs ridge structures 10-100 fold as the oxidation front progresses inward. The reduction of propagation scattering loss due to the reduced sidewall roughness is examined. The thermal oxide grown on the deeply-etched RWG sidewalls and base also provides electrical isolation from the contact metallization, resulting in a simplified, self-aligned process, and yields a RWG structure which effectively prevents current spreading. The thermal oxide appears to be of sufficiently high quality to passivate the etched active region surface based on a comparative analysis of straight RWG lasers of varying stripe widths (w=5 to 150 μm) passivated with native-oxide vs. PECVD-deposited SiO II. For example, at w<15 μm, the SiO II-insulated devices have ~2X higher threshold current densities than the native-oxide devices for comparable bar lengths. The resulting high lateral optical confinement factor at the semiconductor/oxide interface (Δn=1.69) significantly enhances the laser gain and efficiency. A native-oxide-defined straight laser (w=7 μm, L= 452 μm) operates cw (300 K, unbonded, p-side up) with a threshold current of I th=21.5 mA (J th=679.5 A/cm2) and slope efficiency of 1.19 A/W (differential quantum efficiency = 78%) at a wavelength of ~813 nm.
A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabricatio... more A simple, novel self-aligned deeply-etched plus wet thermally oxidized ridge waveguide fabrication process is demonstrated which enables high-index-contrast, low loss curved resonator GRINSCH lasers with a bend radius as low as 10 μm.
A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which... more A simple, novel self-aligned deep etch plus wet thermal oxidization process is demonstrated which enables high-index-contrast (HIC) ridge waveguide (RWG) lasers fabricated in a high-efficiency, high-power AlGaAs/InAlGaAs/GaAs graded-index separate confinement heterostructure to operate with a curved half-ring resonator geometry having a bend radius as low as 10 μm. A wet thermal oxidation process modified through addition of <1% O II to the N 2 carrier gas is shown to smooth the sidewall roughness of etched AlGaAs ridge structures 10-100 fold as the oxidation front progresses inward. The reduction of propagation scattering loss due to the reduced sidewall roughness is examined. The thermal oxide grown on the deeply-etched RWG sidewalls and base also provides electrical isolation from the contact metallization, resulting in a simplified, self-aligned process, and yields a RWG structure which effectively prevents current spreading. The thermal oxide appears to be of sufficiently high quality to passivate the etched active region surface based on a comparative analysis of straight RWG lasers of varying stripe widths (w=5 to 150 μm) passivated with native-oxide vs. PECVD-deposited SiO II. For example, at w<15 μm, the SiO II-insulated devices have ~2X higher threshold current densities than the native-oxide devices for comparable bar lengths. The resulting high lateral optical confinement factor at the semiconductor/oxide interface (Δn=1.69) significantly enhances the laser gain and efficiency. A native-oxide-defined straight laser (w=7 μm, L= 452 μm) operates cw (300 K, unbonded, p-side up) with a threshold current of I th=21.5 mA (J th=679.5 A/cm2) and slope efficiency of 1.19 A/W (differential quantum efficiency = 78%) at a wavelength of ~813 nm.
A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated u... more A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated using a wet thermal oxidation process modified through addition of <1% O2 to the N2 carrier gas, potentially enabling high index contrast waveguides with ultra-low scattering loss for ring resonator and other photonics device applications
IEEE Photonics Technology Letters, 2007
A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated u... more A 10-100 fold reduction in sidewall roughness of etched AlGaAs ridge structures is demonstrated using a wet thermal oxidation process modified through addition of <1% O2 to the N2 carrier gas, potentially enabling high index contrast waveguides with ultra-low scattering loss for ring resonator and other photonics device applications