A low phase noise millimeter-wave(MMW) signal generator is proposed and experimentally demonstrated with a C-band passively Fabry-Pérot(F-P) quantum dot mode-locked laser. A novel method is proposed to generate l...A low phase noise millimeter-wave(MMW) signal generator is proposed and experimentally demonstrated with a C-band passively Fabry-Pérot(F-P) quantum dot mode-locked laser. A novel method is proposed to generate low phase noise MMW signal, which is simply based on a commercial off-the-shelf dual-driven Li Nb O3 Mach-Zehnder modulator and a passively F-P quantum dot mode-locked laser. MMW signal with the frequency of 30 GHz, 45 GHz and 90 GHz respectively is obtained experimentally. Single-sideband phase noise of the 30 GHz and 45 GHz MMW signal is-112 d Bc/Hz and-106 d Bc/Hz at an offset of 1 k Hz, respectively. The linewidth of the 30 GHz and 45 GHz MMW signal is about from 225 Hz and 239 Hz. This is considered a very simple MMW generator with a quasi-tunable broadband and ultra-low phase noise.展开更多
Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It...Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It is observed that the photoluminescence （PL） intensity of bulk InGaAs materials is enhanced after low dose electron irradiation and the PL intensity for all the three samples is degraded dramatically when the electron dose is relatively high. With respect to the room-temperature annealing, we find that the PL intensity for both samples recovers relatively fast at the initial stage. The PL performance of multiple quantum-well samples shows better recovery after irradiation compared with the results of bulk InGaAs materials. Meanwhile, the recovery speed factors of multiple quantum-well samples are relatively faster than those of the bulk InGaAs materials as well. We infer that the recovery difference between the quantum-well materials and bulk materials originates from the fact that the radiation induced defects are confined in the quantum wells as a consequence of the free energy barrier between the In0.53Ga0.47 As wells and InP barrier layers.展开更多
We report on a three-colour InAs/InP(100)quantum dot laser under continuous wave mode at an operation temperature of 20℃.Three lasing peaks are observed simultaneously,the high-energy peak undergoes continuous bluesh...We report on a three-colour InAs/InP(100)quantum dot laser under continuous wave mode at an operation temperature of 20℃.Three lasing peaks are observed simultaneously,the high-energy peak undergoes continuous blueshift,while the splitting energy gap between the low-energy peaks is somewhat fixed as the injection current increases.The maximum output power from one facet without coating is more than 34mW with a slope efficiency of 102mW/A just above the threshold current.Three peaks of differential efficiency of output power are observed,just corresponding to each peak in lasing spectra,respectively.At the same time,the far-field distribution shows only a single transverse mode over the full range of injection current.展开更多
Growth of ln0.52Al0.48As epitaxial layers on lnP(100) substrates by molecular beam epitaxy at a wide range of arsenic overpressures (V/III flux ratios from 30 to 300) has been carried out. Analysis performed using low...Growth of ln0.52Al0.48As epitaxial layers on lnP(100) substrates by molecular beam epitaxy at a wide range of arsenic overpressures (V/III flux ratios from 30 to 300) has been carried out. Analysis performed using low-temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) shows a strong and prominent dependence of the PL and XRD linewidths on the V/III flux ratio. Under our growth conditions, both the PL and XRD linewidths exhibit a minimum point at a V/III flux ratio of 150 which corresponds to a maximum in the PL intensity and XRD intensity ratio. Flux ratios exceeding 150 result in an increase in both the PL and XRD linewidths corresponding to a reduction in their associated intensities. Room temperature Raman scattering measurements show a narrowing in the lnAs-like and AlAs-like longitudinal-optic (LO)phonon linewidths which broaden at high flux ratios, while the LO phonon frequencies exhibit a gradual reduction as the flux ratio is increased. PL spectra taken at increasing temperatures show a quenching of the main emission peak followed by the evolution of a broad lower energy emission which is possibly associated with deep lying centres. This effect is more prominent in samples grown at lower V/III flux ratios. Hall effect measurements show a gradual reduction in the mobility in correspondence to an increase in the electron concentration as the flux ratio is increased.展开更多
We examine the saturation of relative current gain of Ino.53Gao.47As/InP single photon avalanche diodes （SPADs） operated in Geiger mode. The punch-through voltage and breakdown voltage of the SPADs can be measured u...We examine the saturation of relative current gain of Ino.53Gao.47As/InP single photon avalanche diodes （SPADs） operated in Geiger mode. The punch-through voltage and breakdown voltage of the SPADs can be measured using a simple and accurate method. The analysis method is temperature-independent and can be applied to most SPADs.展开更多
基金supported by the Humanity and Social Science Foundation of Chinese Ministry of Education (No.19YJC880053)the Natural Science Foundation of Zhejiang Province (No.LQ18F010008)+3 种基金the Philosophy and Social Science Planning Project of Zhejiang Province (No.19NDJC0103YB)the Natural Science Foundation of Ningbo (No.2018A610092)the Research Fund Project of Ningbo Institute of Finance&Economics (No.1320171002)the Education and Teaching Reform Program of Ningbo Institute of Finance&Economics (No.20jyyb16)。
文摘A low phase noise millimeter-wave(MMW) signal generator is proposed and experimentally demonstrated with a C-band passively Fabry-Pérot(F-P) quantum dot mode-locked laser. A novel method is proposed to generate low phase noise MMW signal, which is simply based on a commercial off-the-shelf dual-driven Li Nb O3 Mach-Zehnder modulator and a passively F-P quantum dot mode-locked laser. MMW signal with the frequency of 30 GHz, 45 GHz and 90 GHz respectively is obtained experimentally. Single-sideband phase noise of the 30 GHz and 45 GHz MMW signal is-112 d Bc/Hz and-106 d Bc/Hz at an offset of 1 k Hz, respectively. The linewidth of the 30 GHz and 45 GHz MMW signal is about from 225 Hz and 239 Hz. This is considered a very simple MMW generator with a quasi-tunable broadband and ultra-low phase noise.
文摘Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It is observed that the photoluminescence （PL） intensity of bulk InGaAs materials is enhanced after low dose electron irradiation and the PL intensity for all the three samples is degraded dramatically when the electron dose is relatively high. With respect to the room-temperature annealing, we find that the PL intensity for both samples recovers relatively fast at the initial stage. The PL performance of multiple quantum-well samples shows better recovery after irradiation compared with the results of bulk InGaAs materials. Meanwhile, the recovery speed factors of multiple quantum-well samples are relatively faster than those of the bulk InGaAs materials as well. We infer that the recovery difference between the quantum-well materials and bulk materials originates from the fact that the radiation induced defects are confined in the quantum wells as a consequence of the free energy barrier between the In0.53Ga0.47 As wells and InP barrier layers.
基金by the Natural Foundation of Guangdong Province under Grant Nos S2011040001330。
文摘We report on a three-colour InAs/InP(100)quantum dot laser under continuous wave mode at an operation temperature of 20℃.Three lasing peaks are observed simultaneously,the high-energy peak undergoes continuous blueshift,while the splitting energy gap between the low-energy peaks is somewhat fixed as the injection current increases.The maximum output power from one facet without coating is more than 34mW with a slope efficiency of 102mW/A just above the threshold current.Three peaks of differential efficiency of output power are observed,just corresponding to each peak in lasing spectra,respectively.At the same time,the far-field distribution shows only a single transverse mode over the full range of injection current.
文摘Growth of ln0.52Al0.48As epitaxial layers on lnP(100) substrates by molecular beam epitaxy at a wide range of arsenic overpressures (V/III flux ratios from 30 to 300) has been carried out. Analysis performed using low-temperature photoluminescence (PL) and double-axis X-ray diffraction (XRD) shows a strong and prominent dependence of the PL and XRD linewidths on the V/III flux ratio. Under our growth conditions, both the PL and XRD linewidths exhibit a minimum point at a V/III flux ratio of 150 which corresponds to a maximum in the PL intensity and XRD intensity ratio. Flux ratios exceeding 150 result in an increase in both the PL and XRD linewidths corresponding to a reduction in their associated intensities. Room temperature Raman scattering measurements show a narrowing in the lnAs-like and AlAs-like longitudinal-optic (LO)phonon linewidths which broaden at high flux ratios, while the LO phonon frequencies exhibit a gradual reduction as the flux ratio is increased. PL spectra taken at increasing temperatures show a quenching of the main emission peak followed by the evolution of a broad lower energy emission which is possibly associated with deep lying centres. This effect is more prominent in samples grown at lower V/III flux ratios. Hall effect measurements show a gradual reduction in the mobility in correspondence to an increase in the electron concentration as the flux ratio is increased.
基金supported by the National Basic Research Program (973 Program) of China (Nos.G2001039302 and 007CB307001)the Guangdong Key Technologies R&D Program (No.2007B010400009)
文摘We examine the saturation of relative current gain of Ino.53Gao.47As/InP single photon avalanche diodes （SPADs） operated in Geiger mode. The punch-through voltage and breakdown voltage of the SPADs can be measured using a simple and accurate method. The analysis method is temperature-independent and can be applied to most SPADs.
基金Supported by 863 Program of China(2011AA010205)National Major Basic Research Project(2011CB925603)Natural Science Foundation of China(91221201,61234005,11074167)
