With a chirped InAs/GaAs SML-QD （quantum dot） structure serving as the active region, the superluminescent diodes emitting at wavelength of around 970nm are fabricated. By using an active multimode interferometer co...With a chirped InAs/GaAs SML-QD （quantum dot） structure serving as the active region, the superluminescent diodes emitting at wavelength of around 970nm are fabricated. By using an active multimode interferometer configuration, these devices exhibit high continue-wave output powers from the narrow ridge waveguides. At continue-wave injection current of 800mA, an output power of 18.5mW, and the single Gaussian-like emission spectrum centered at 972nm with a full width at half maximum of 18nm are obtained.展开更多
This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAl- GaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full widt...This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAl- GaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output power of 18 mW. By incorporating an Al composition into the quan- tum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent-waveguide facet, respectively. The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. A numerical simulation is performed to verify the qualitative explanation. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices.展开更多
According to the InAs/GaAs submonolayer quantum dot active region, we demonstrate a bent-waveguide superluminescent diode emitting at a wavelength of around 970 nm. At a pulsed injection current of 0.5 A, the device e...According to the InAs/GaAs submonolayer quantum dot active region, we demonstrate a bent-waveguide superluminescent diode emitting at a wavelength of around 970 nm. At a pulsed injection current of 0.5 A, the device exhibits an output power of 24 mW and an emission spectrum centred at 971 nm with a full width at half maximum of 16 nm.展开更多
We present a stochastic procedure to investigate the correlation spectra of quantum dot superluminescent diodes. The classical electric field of a diode is formed by a polychromatic superposition of many independent s...We present a stochastic procedure to investigate the correlation spectra of quantum dot superluminescent diodes. The classical electric field of a diode is formed by a polychromatic superposition of many independent stochastic oscillators. Assuming fields with individual carrier frequencies, Lorentzian linewidths and amplitudes we can form any relevant experimental spectrum using a least square fit. This is illustrated for Gaussian and Lorentzian spectra, Voigt profiles and box shapes. Eventually, the procedure is applied to an experimental spectrum of a quantum dot superluminescent diode which determines the first- and second-order temporal correlation functions of the emission. We find good agreement with the experimental data and a quantized treatment. Thus, a superposition of independent stochastic oscillators represents the first- and second-order correlation properties of broadband light emitted by quantum dot superluminescent diodes.展开更多
We report the effect of the GaAs spacer layer thickness on the photoluminescence （PL） spectral bandwidth of InAs/GaAs self-assembled quantum dots （QDs）. A PL spectral bandwidth of 158 nm is achieved with a five-la...We report the effect of the GaAs spacer layer thickness on the photoluminescence （PL） spectral bandwidth of InAs/GaAs self-assembled quantum dots （QDs）. A PL spectral bandwidth of 158 nm is achieved with a five-layer stack of InAs QDs which has a 11-nm thick GaAs spacer layer. We investigate the optical and the structurM properties of the multilayer-stacked InAs/GaAs QDs with different GaAs spacer layer thicknesses. The results show that the spacer thickness is a key parameter affecting the multi-stacked InAs/GaAs QDs for wide-spectrum emission.展开更多
The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and op...The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and optimization, it will be helpful if this bend loss can be estimated. In this letter, we have derived an analytical formula which can be used to get the bend-loss coefficient by fitting the P-I curves of the devices. It is proved that the formula is successful in estimating the loss coefficients from the P-I curves simulated from a complicated quantum-dot device model. We expect this method could also be valid in estimating bend losses of actual devices.展开更多
We report a new quantum dot superluminescent diode with a new device structure. In this device, a multi- mode-interferometer configuration and a J-bend structure were monolithically integrated. Owing to the multi-mode...We report a new quantum dot superluminescent diode with a new device structure. In this device, a multi- mode-interferometer configuration and a J-bend structure were monolithically integrated. Owing to the multi-mode- interferometer structure, the superluminescent diode exhibits 60% increase in output power and 43% reduction in the differential resistance compared with the uniform waveguide width superluminescent diode fabricated from the same wafer. Our device produces an emission spectrum as wide as 103.7 nm with an output power of 2.5 mW at 600 mA continue-wave injection current. This broadband emission spectrum makes the axial resolution of the optical coherence tomography system employing the superluminescent diode to 6 μm in theory, which is high enough for most tissue imaging.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2006CB604904)the National Natural Science Foundation of China (Grant Nos. 60976057, 61274072, and 60876086)
文摘With a chirped InAs/GaAs SML-QD （quantum dot） structure serving as the active region, the superluminescent diodes emitting at wavelength of around 970nm are fabricated. By using an active multimode interferometer configuration, these devices exhibit high continue-wave output powers from the narrow ridge waveguides. At continue-wave injection current of 800mA, an output power of 18.5mW, and the single Gaussian-like emission spectrum centered at 972nm with a full width at half maximum of 18nm are obtained.
基金supported by the National Basic Research Program of China (Grant No. 2006CB604904)the National Natural Science Foundation of China (Grant Nos. 60876086, 60976057, and 60776037)
文摘This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAl- GaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output power of 18 mW. By incorporating an Al composition into the quan- tum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent-waveguide facet, respectively. The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. A numerical simulation is performed to verify the qualitative explanation. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices.
基金supported by the National Basic Research Program of China (Grant No.2006CB604904)the National Natural Science Foundation of China (Grant Nos.60876086,60976057,and 60776037)
文摘According to the InAs/GaAs submonolayer quantum dot active region, we demonstrate a bent-waveguide superluminescent diode emitting at a wavelength of around 970 nm. At a pulsed injection current of 0.5 A, the device exhibits an output power of 24 mW and an emission spectrum centred at 971 nm with a full width at half maximum of 16 nm.
文摘We present a stochastic procedure to investigate the correlation spectra of quantum dot superluminescent diodes. The classical electric field of a diode is formed by a polychromatic superposition of many independent stochastic oscillators. Assuming fields with individual carrier frequencies, Lorentzian linewidths and amplitudes we can form any relevant experimental spectrum using a least square fit. This is illustrated for Gaussian and Lorentzian spectra, Voigt profiles and box shapes. Eventually, the procedure is applied to an experimental spectrum of a quantum dot superluminescent diode which determines the first- and second-order temporal correlation functions of the emission. We find good agreement with the experimental data and a quantized treatment. Thus, a superposition of independent stochastic oscillators represents the first- and second-order correlation properties of broadband light emitted by quantum dot superluminescent diodes.
基金Project supported by the National Basic Research Program of China (Grant No. 2006CB604904)the National Natural Science Foundation of China (Grant Nos. 60976057,61274072,and 60776037)
文摘We report the effect of the GaAs spacer layer thickness on the photoluminescence （PL） spectral bandwidth of InAs/GaAs self-assembled quantum dots （QDs）. A PL spectral bandwidth of 158 nm is achieved with a five-layer stack of InAs QDs which has a 11-nm thick GaAs spacer layer. We investigate the optical and the structurM properties of the multilayer-stacked InAs/GaAs QDs with different GaAs spacer layer thicknesses. The results show that the spacer thickness is a key parameter affecting the multi-stacked InAs/GaAs QDs for wide-spectrum emission.
基金Project supported by the National Natural Science Foundation of China(Nos.61274072,60976057)
文摘The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and optimization, it will be helpful if this bend loss can be estimated. In this letter, we have derived an analytical formula which can be used to get the bend-loss coefficient by fitting the P-I curves of the devices. It is proved that the formula is successful in estimating the loss coefficients from the P-I curves simulated from a complicated quantum-dot device model. We expect this method could also be valid in estimating bend losses of actual devices.
基金supported by the National Natural Science Foundation of China(No.61274072)the National High Technology Research and Development Program of China(No.2013AA014201)
文摘We report a new quantum dot superluminescent diode with a new device structure. In this device, a multi- mode-interferometer configuration and a J-bend structure were monolithically integrated. Owing to the multi-mode- interferometer structure, the superluminescent diode exhibits 60% increase in output power and 43% reduction in the differential resistance compared with the uniform waveguide width superluminescent diode fabricated from the same wafer. Our device produces an emission spectrum as wide as 103.7 nm with an output power of 2.5 mW at 600 mA continue-wave injection current. This broadband emission spectrum makes the axial resolution of the optical coherence tomography system employing the superluminescent diode to 6 μm in theory, which is high enough for most tissue imaging.
