A high-sensitivity plasmonic refractive-index sensor based on the asymmetrical coupling of two metal-insulator- metal waveguides with a nanodisk resonator is proposed and simulated in the finite-difference time domain...A high-sensitivity plasmonic refractive-index sensor based on the asymmetrical coupling of two metal-insulator- metal waveguides with a nanodisk resonator is proposed and simulated in the finite-difference time domain. Both analytic and simulated results show that the resonance wavelengths of the sensor have an approximate linear relationship with the refractive index of the materials which are filled into the slit waveguides and the disk- shaped resonator. The working mechanism of this sensor is exactly due to the linear relationship, based on which tile refractive index of the materials unknown can be obtained from the detection of the resonance wavelength. The measurement sensitivity can reach as high as 6.45 × 10-7, which is nearly five times higher than the results reported in the recent literature [Opt. Commun. 300 （2013） 265]. With an optimum design, the sensing value can be further improved, and it can be widely applied into the biological sensing. Tile sensor working for temperature sensing is also analyzed.展开更多
A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymm...A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymmetric twin waveguide technology. A 1550-1600nm lossless operation with a high DC extinction ratio of 25dB and more than 10GHz 3dB bandwidth are successfully achieved. The output beam divergence angles of the device in the horizontal and vertical directions are as small as 7.3°× 18.0°, respectively, resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.展开更多
The effects of Ga N/In Ga N asymmetric lower waveguide(LWG)layers on photoelectrical properties of In Ga N multiple quantum well laser diodes(LDs)with an emission wavelength of around 416 nm are theoretically investig...The effects of Ga N/In Ga N asymmetric lower waveguide(LWG)layers on photoelectrical properties of In Ga N multiple quantum well laser diodes(LDs)with an emission wavelength of around 416 nm are theoretically investigated by tuning the thickness and the indium content of In Ga N insertion layer(In Ga N-IL)between the Ga N lower waveguide layer and the quantum wells,which is achieved with the Crosslight Device Simulation Software(PIC3D,Crosslight Software Inc.).The optimal thickness and the indium content of the In Ga N-IL in lower waveguide layers are found to be 300 nm and 4%,respectively.The thickness of In Ga N-IL predominantly affects the output power and the optical field distribution in comparison with the indium content,and the highest output power is achieved to be 1.25 times that of the reference structure(symmetric Ga N waveguide),which is attributed to the reduced optical absorption loss as well as the concentrated optical field nearby quantum wells.Furthermore,when the thickness and indium content of In Ga N-IL both reach a higher level,the performance of asymmetric quantum wells LDs will be weakened rapidly due to the obvious decrease of optical confinement factor(OCF)related to the concentrated optical field in the lower waveguide.展开更多
We investigate the guided modes in monolayer graphene-based waveguides with asymmetric quantum well structure induced by unequal dc voltages. The dispersion relation for the guided modes is obtained analytically, the ...We investigate the guided modes in monolayer graphene-based waveguides with asymmetric quantum well structure induced by unequal dc voltages. The dispersion relation for the guided modes is obtained analytically, the structures of the guided modes are discussed under three distinct cases. For the cases of the classical motion and the Klein tunneling, the asymmetric structure does not influence the mode structures dramatically compared with that in the symmetric waveguide. But for the mixing case of the former two, the mode structures and the motion characteristics for the electron and the hole exhibit different behaviors at same condition. The results may be helpful for the practical application of graphene-based quantum devices.展开更多
The 810-nm InGaAlAs/AlGaAs double quantum well （QW） semiconductor lasers with asymmetric waveguide structures, grown by molecular beam epitaxy, show high quantum efficiency and high-power conver- sion efficiency at ...The 810-nm InGaAlAs/AlGaAs double quantum well （QW） semiconductor lasers with asymmetric waveguide structures, grown by molecular beam epitaxy, show high quantum efficiency and high-power conver- sion efficiency at continuous-wave （CW） power output. The threshold current density and slope efficiency of the device are 180 A/cm^2 and 1.3 W/A, respectively. The internal loss and the internal quantum efficiency are 1.7 cm^-1 and 93%, respectively. The 70% maximum power conversion efficiency is achieved with narrow far-field patterns.展开更多
A novel asymmetric broad waveguide diode laser structure was designed for high power conversion efficiency（PCE）.The internal quantum efficiency,the series resistance,and the thermal resistance were theoretically opt...A novel asymmetric broad waveguide diode laser structure was designed for high power conversion efficiency（PCE）.The internal quantum efficiency,the series resistance,and the thermal resistance were theoretically optimized.The series resistance and the thermal resistance were greatly decreased by optimizing the thickness of the P-waveguide and the P-cladding layers.The internal quantum efficiency was increased by introducing a novel strain-compensated GaAs0.9P0.1/InGaAs quantum well.Experimentally,a single 1-cm bar with 20% fill factor and 900 μm cavity length was mounted P-side down on a microchannel-cooled heatsink,and a peak PCE of 60% is obtained at 26.3-W continuous wave output power.The results prove that this novel asymmetric waveguide structure design is an efficient approach to improve the PCE.展开更多
Complicated multilevel micro/nanostructures have attracted great attention as essential basic components of integrated optoelectronic devices.However,precise synthesis of these well-designed micro/nanostructures is st...Complicated multilevel micro/nanostructures have attracted great attention as essential basic components of integrated optoelectronic devices.However,precise synthesis of these well-designed micro/nanostructures is still a major challenge.In this report,a series of near-infrared emissive multilevel branched organic microwires with different integrated levels are successfully fabricated for the first time by a facile self-assembly approach based on our well designed and synthesized(2E,2′E)-1,1′-(1,5-dihydroxynaphthalene-2,6-diyl)bis(3-(4-(dimethylamino)phenyl)prop-2-en-1-one)(DHNBP).The growth mechanism is attributed to lattice matching between(100)and(010)crystal planes,with an interplanar spacing mismatch rate as low as 5.3%.Benefiting from the uniaxial oriented molecular packing mode of the crystal,the well-prepared microwires have outstanding optical properties.More significantly,the branched structures can work as optical logic gates and optical signal processors.Therefore,this synthesis method for multilevel branched microwires will potentially facilitate the development of organic integrated optoelectronics.展开更多
The high power and low internal loss 1.06 μm InGaAs/GaAsP quantum well lasers with asymmetric waveguide structure were designed and fabricated. For a 4000 μm cavity length and 100 μm stripe width device,the maximum...The high power and low internal loss 1.06 μm InGaAs/GaAsP quantum well lasers with asymmetric waveguide structure were designed and fabricated. For a 4000 μm cavity length and 100 μm stripe width device,the maximum output power and conversion efficiency of the device are 7.13 W and 56.4%, respectively. The cavity length dependence of the threshold current density and conversion efficiency have been investigated theoretically and experimentally; the laser diode with 4000 μm cavity length shows better characteristics than that with 3000 and 4500 μm cavity length： the threshold current density is 132.5 A/cm^2, the slope efficiency of 1.00 W/A and the junction temperature of 15.62 K were achieved.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61275059
文摘A high-sensitivity plasmonic refractive-index sensor based on the asymmetrical coupling of two metal-insulator- metal waveguides with a nanodisk resonator is proposed and simulated in the finite-difference time domain. Both analytic and simulated results show that the resonance wavelengths of the sensor have an approximate linear relationship with the refractive index of the materials which are filled into the slit waveguides and the disk- shaped resonator. The working mechanism of this sensor is exactly due to the linear relationship, based on which tile refractive index of the materials unknown can be obtained from the detection of the resonance wavelength. The measurement sensitivity can reach as high as 6.45 × 10-7, which is nearly five times higher than the results reported in the recent literature [Opt. Commun. 300 （2013） 265]. With an optimum design, the sensing value can be further improved, and it can be widely applied into the biological sensing. Tile sensor working for temperature sensing is also analyzed.
文摘A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymmetric twin waveguide technology. A 1550-1600nm lossless operation with a high DC extinction ratio of 25dB and more than 10GHz 3dB bandwidth are successfully achieved. The output beam divergence angles of the device in the horizontal and vertical directions are as small as 7.3°× 18.0°, respectively, resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.
基金the National Natural Science Foundation of China(Grant Nos.62004180 and 61805218)the Science Challenge Project,China(Grant No.TZ20160032-1)the National Key Research and Development Program of China(Grant Nos.2017YFB0403100 and 2017YFB0403103)。
文摘The effects of Ga N/In Ga N asymmetric lower waveguide(LWG)layers on photoelectrical properties of In Ga N multiple quantum well laser diodes(LDs)with an emission wavelength of around 416 nm are theoretically investigated by tuning the thickness and the indium content of In Ga N insertion layer(In Ga N-IL)between the Ga N lower waveguide layer and the quantum wells,which is achieved with the Crosslight Device Simulation Software(PIC3D,Crosslight Software Inc.).The optimal thickness and the indium content of the In Ga N-IL in lower waveguide layers are found to be 300 nm and 4%,respectively.The thickness of In Ga N-IL predominantly affects the output power and the optical field distribution in comparison with the indium content,and the highest output power is achieved to be 1.25 times that of the reference structure(symmetric Ga N waveguide),which is attributed to the reduced optical absorption loss as well as the concentrated optical field nearby quantum wells.Furthermore,when the thickness and indium content of In Ga N-IL both reach a higher level,the performance of asymmetric quantum wells LDs will be weakened rapidly due to the obvious decrease of optical confinement factor(OCF)related to the concentrated optical field in the lower waveguide.
基金Supported by the Natural Science Foundation of China under Grant No.11204383the Fundamental Research Funds for the Central Universities of South-Central University for Nationalities under Grant No.CZQ11001+2 种基金the Natural Science Basic Research Plan in Shaanxi Province of China under Grant No.11JK0556the Scientific Research Program of Shaanxi Provincial Education Department under Grant No.2011JM1014the National Natural Science Foundation of Shaanxi University of Science and Technology under Grant No.ZX11-33
文摘We investigate the guided modes in monolayer graphene-based waveguides with asymmetric quantum well structure induced by unequal dc voltages. The dispersion relation for the guided modes is obtained analytically, the structures of the guided modes are discussed under three distinct cases. For the cases of the classical motion and the Klein tunneling, the asymmetric structure does not influence the mode structures dramatically compared with that in the symmetric waveguide. But for the mixing case of the former two, the mode structures and the motion characteristics for the electron and the hole exhibit different behaviors at same condition. The results may be helpful for the practical application of graphene-based quantum devices.
文摘The 810-nm InGaAlAs/AlGaAs double quantum well （QW） semiconductor lasers with asymmetric waveguide structures, grown by molecular beam epitaxy, show high quantum efficiency and high-power conver- sion efficiency at continuous-wave （CW） power output. The threshold current density and slope efficiency of the device are 180 A/cm^2 and 1.3 W/A, respectively. The internal loss and the internal quantum efficiency are 1.7 cm^-1 and 93%, respectively. The 70% maximum power conversion efficiency is achieved with narrow far-field patterns.
文摘A novel asymmetric broad waveguide diode laser structure was designed for high power conversion efficiency（PCE）.The internal quantum efficiency,the series resistance,and the thermal resistance were theoretically optimized.The series resistance and the thermal resistance were greatly decreased by optimizing the thickness of the P-waveguide and the P-cladding layers.The internal quantum efficiency was increased by introducing a novel strain-compensated GaAs0.9P0.1/InGaAs quantum well.Experimentally,a single 1-cm bar with 20% fill factor and 900 μm cavity length was mounted P-side down on a microchannel-cooled heatsink,and a peak PCE of 60% is obtained at 26.3-W continuous wave output power.The results prove that this novel asymmetric waveguide structure design is an efficient approach to improve the PCE.
基金financially supported by the National Natural Science Foundation of China(21971185,51821002)China Postdoctoral Science Foundation(2020M681707)+1 种基金the Collaborative Innovation Center of Suzhou Nano Science and Technology(CIC-Nano)the"111"Project of the State Administration of Foreign Experts Affairs of China。
文摘Complicated multilevel micro/nanostructures have attracted great attention as essential basic components of integrated optoelectronic devices.However,precise synthesis of these well-designed micro/nanostructures is still a major challenge.In this report,a series of near-infrared emissive multilevel branched organic microwires with different integrated levels are successfully fabricated for the first time by a facile self-assembly approach based on our well designed and synthesized(2E,2′E)-1,1′-(1,5-dihydroxynaphthalene-2,6-diyl)bis(3-(4-(dimethylamino)phenyl)prop-2-en-1-one)(DHNBP).The growth mechanism is attributed to lattice matching between(100)and(010)crystal planes,with an interplanar spacing mismatch rate as low as 5.3%.Benefiting from the uniaxial oriented molecular packing mode of the crystal,the well-prepared microwires have outstanding optical properties.More significantly,the branched structures can work as optical logic gates and optical signal processors.Therefore,this synthesis method for multilevel branched microwires will potentially facilitate the development of organic integrated optoelectronics.
文摘The high power and low internal loss 1.06 μm InGaAs/GaAsP quantum well lasers with asymmetric waveguide structure were designed and fabricated. For a 4000 μm cavity length and 100 μm stripe width device,the maximum output power and conversion efficiency of the device are 7.13 W and 56.4%, respectively. The cavity length dependence of the threshold current density and conversion efficiency have been investigated theoretically and experimentally; the laser diode with 4000 μm cavity length shows better characteristics than that with 3000 and 4500 μm cavity length： the threshold current density is 132.5 A/cm^2, the slope efficiency of 1.00 W/A and the junction temperature of 15.62 K were achieved.
