We proposed a new model for controlling the optical bistability（OB） and optical multistability（OM） in a defect slab doped with four-level GaAs/AlGaAs multiple quantum wells with 15 periods of 17.5 nm GaAs wells an...We proposed a new model for controlling the optical bistability（OB） and optical multistability（OM） in a defect slab doped with four-level GaAs/AlGaAs multiple quantum wells with 15 periods of 17.5 nm GaAs wells and 15-nm Al_（0.3）Ga_（0.7）As barriers. The effects of biexciton energy renormalization, exciton spin relaxation, and thickness of the slab on the OB and OM properties of the defect slab were theoretically investigated. We found that the transition from OB to OM or vice versa is possible by adjusting the controllable parameters in a lab. Moreover, the transmission, reflection, and absorption properties of the weak probe light through the slab were also discussed in detail.展开更多
The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can...The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing.展开更多
We study the optical amplification and absorption properties in a double-Λ four level system of GaAs/AlGaAs multiple quantum wells(MQWs) under realistic experimental conditions.The amplification and absorption respon...We study the optical amplification and absorption properties in a double-Λ four level system of GaAs/AlGaAs multiple quantum wells(MQWs) under realistic experimental conditions.The amplification and absorption responses of two weak fields can be achieved by adjusting the relative phase,the probe detuning,and the two pump Rabi frequencies appropriately.The investigation is much more practical than its atomic counterpart because of its flexible design and the wide adjustable parameters.It may provide a new possibility in technological applications for the light amplifier working on quantum coherence effects in MQWs solid-state system.展开更多
BaTiO3 （BTO） ferroelectric thin films are prepared by the sol,el method. The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode （LED） with amorphous BTO ferroelectric...BaTiO3 （BTO） ferroelectric thin films are prepared by the sol,el method. The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode （LED） with amorphous BTO ferroelectric thin film are studied. The photolumineseence （PL） of the BTO ferroelectric film is attributed to the structure. The ferroeleetric film which annealed at 673 K for 8 h has the better PL property. The peak width is about 30 nm from 580 nm to 610 nm, towards the yellow region. The mixed electroluminescence （EL） spectrum of InGaN/GaN multiple quantum well LED with 150-nm thick amorphous BTO ferroelectric thin film displays the blue-white light. The Commission Internationale De L＇Eclairage （CIE） coordinate of EL is （0.2139, 0.1627）. EL wavelength and intensity depends on the composition, microstructure and thickness of the ferroelectric thin film. The transmittance of amorphous BTO thin film is about 93% at a wavelength of 450 nm-470 nm. This means the amorphous ferroelectrie thin films can output more blue-ray and emission lights. In addition, the amorphous ferroelectric thin films can be directly fabricated without a binder and used at higher temperatures （200 ℃-400 ℃）. It is very favourable to simplify the preparation process and reduce the heat dissipation requirements of an LED. This provides a new way to study LEDs.展开更多
Using beam propagation method （BPM）, key optical design parameters of InP/AlGaInAs multiple quantumwell （MQW） ring laser were numerically analyzed. The influences of waveguide dimensions, curvature radiusand gap s...Using beam propagation method （BPM）, key optical design parameters of InP/AlGaInAs multiple quantumwell （MQW） ring laser were numerically analyzed. The influences of waveguide dimensions, curvature radiusand gap size on the coupling efficiency were discussed. An InP/AlGaInAs MQW ring laser with radius of 350 μm wasdesigned and realized. The experimental results show that the designed device, lasing at 1 563.2 nm with side modesuppression ratio higher than 20 dB, exhibited unidirectional bistability between the clockwise and counterclockwisemodes.展开更多
Based on InAlGaAs multi-quantum wells epitaxy structure for Fabry-Pero laser diode,a multi-quantum wells semiconductor ring laser is realized using ICP dry etching process and polyimide planarization process.The laser...Based on InAlGaAs multi-quantum wells epitaxy structure for Fabry-Pero laser diode,a multi-quantum wells semiconductor ring laser is realized using ICP dry etching process and polyimide planarization process.The laser is generated in a semiconductor resonator ring and is output by two coupled integrated bus waveguides.The ring diameter is 700 μm and the width of the waveguide is 3 μm.The output optical power-current(P-I) characteristic and the wavelength spectra of the ring laser are measured using a fiber coupled to the cleaved facet of the bus waveguide.The threshold current of the device is 120 mA and the wavelength is 1602 nm at an injected current of 160 mA.In addition,the operation mode for the laser in the resonator ring is roughly discussed based on the P-I characteristic plot.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
文摘We proposed a new model for controlling the optical bistability（OB） and optical multistability（OM） in a defect slab doped with four-level GaAs/AlGaAs multiple quantum wells with 15 periods of 17.5 nm GaAs wells and 15-nm Al_（0.3）Ga_（0.7）As barriers. The effects of biexciton energy renormalization, exciton spin relaxation, and thickness of the slab on the OB and OM properties of the defect slab were theoretically investigated. We found that the transition from OB to OM or vice versa is possible by adjusting the controllable parameters in a lab. Moreover, the transmission, reflection, and absorption properties of the weak probe light through the slab were also discussed in detail.
基金supported by the Lithuanian Research Council(Grant No.VP1-3.1-M-01-V-03-001)
文摘The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing.
基金supported by the National Natural Science Foundation of China (60877040)the National Basic Research Program of China(2010CB923204)
文摘We study the optical amplification and absorption properties in a double-Λ four level system of GaAs/AlGaAs multiple quantum wells(MQWs) under realistic experimental conditions.The amplification and absorption responses of two weak fields can be achieved by adjusting the relative phase,the probe detuning,and the two pump Rabi frequencies appropriately.The investigation is much more practical than its atomic counterpart because of its flexible design and the wide adjustable parameters.It may provide a new possibility in technological applications for the light amplifier working on quantum coherence effects in MQWs solid-state system.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61076042 and 60607006)the Special Project on Development of National Key Scientific Instruments and Equipment of China (Grant No. 2011YQ16000205)the National High Technology Research and Development Program of China (Grant No. 2011AA03A106)
文摘BaTiO3 （BTO） ferroelectric thin films are prepared by the sol,el method. The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode （LED） with amorphous BTO ferroelectric thin film are studied. The photolumineseence （PL） of the BTO ferroelectric film is attributed to the structure. The ferroeleetric film which annealed at 673 K for 8 h has the better PL property. The peak width is about 30 nm from 580 nm to 610 nm, towards the yellow region. The mixed electroluminescence （EL） spectrum of InGaN/GaN multiple quantum well LED with 150-nm thick amorphous BTO ferroelectric thin film displays the blue-white light. The Commission Internationale De L＇Eclairage （CIE） coordinate of EL is （0.2139, 0.1627）. EL wavelength and intensity depends on the composition, microstructure and thickness of the ferroelectric thin film. The transmittance of amorphous BTO thin film is about 93% at a wavelength of 450 nm-470 nm. This means the amorphous ferroelectrie thin films can output more blue-ray and emission lights. In addition, the amorphous ferroelectric thin films can be directly fabricated without a binder and used at higher temperatures （200 ℃-400 ℃）. It is very favourable to simplify the preparation process and reduce the heat dissipation requirements of an LED. This provides a new way to study LEDs.
基金Supported by the National Natural Science Foundation of China(No.61106052)
文摘Using beam propagation method （BPM）, key optical design parameters of InP/AlGaInAs multiple quantumwell （MQW） ring laser were numerically analyzed. The influences of waveguide dimensions, curvature radiusand gap size on the coupling efficiency were discussed. An InP/AlGaInAs MQW ring laser with radius of 350 μm wasdesigned and realized. The experimental results show that the designed device, lasing at 1 563.2 nm with side modesuppression ratio higher than 20 dB, exhibited unidirectional bistability between the clockwise and counterclockwisemodes.
基金Supported by the National Natural Science Foundation of China (Grant No.60706035)National Basic Research Program of China (Grant No. 2003CB314901)
文摘Based on InAlGaAs multi-quantum wells epitaxy structure for Fabry-Pero laser diode,a multi-quantum wells semiconductor ring laser is realized using ICP dry etching process and polyimide planarization process.The laser is generated in a semiconductor resonator ring and is output by two coupled integrated bus waveguides.The ring diameter is 700 μm and the width of the waveguide is 3 μm.The output optical power-current(P-I) characteristic and the wavelength spectra of the ring laser are measured using a fiber coupled to the cleaved facet of the bus waveguide.The threshold current of the device is 120 mA and the wavelength is 1602 nm at an injected current of 160 mA.In addition,the operation mode for the laser in the resonator ring is roughly discussed based on the P-I characteristic plot.
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.
