Thermal annealing effect on lnAs quantum dots grown on vicinal （100） GaAs substrates is studied in comparison with dots on exact （100） GaAs substrates. We find that annealing acts stronger effect on dots with vici...Thermal annealing effect on lnAs quantum dots grown on vicinal （100） GaAs substrates is studied in comparison with dots on exact （100） GaAs substrates. We find that annealing acts stronger effect on dots with vicinal substrates by greatly accelerating the degradation of material quality, as well as slightly increasing the blueshift of the emission wavelength and the narrowing of PL linewidth. It is attributed to the higher strain in the dots formed on the vicinal substrates.展开更多
Self-assembled lnAs quantum dots （QDs） are grown on vicinal GaAs （100） substrates by using metal-organic chemical vapour deposition （MOCVD）. An abnormal temperature dependence of bimodal size distribution of InA...Self-assembled lnAs quantum dots （QDs） are grown on vicinal GaAs （100） substrates by using metal-organic chemical vapour deposition （MOCVD）. An abnormal temperature dependence of bimodal size distribution of InAs quantum dots is found. As the temperature increases, the density of the small dots grows larger while the density of the large dots turns smaller, which is contrary to the evolution of QDs on exact GaAs （100） substrates. This trend is explained by taking into account the presence of multiatoinic steps on the substrates. The optical properties of InAs QDs on vicinal GaAs（100） substrates are also studied by photoluminescence （PL） . It is found that dots on a vicinal substrate have a longer emission wavelength, a narrower PL line width and a much larger PL intensity.展开更多
A new device of two parallel distributed feedback （DFB） lasers integrated monolithically with Y-branch waveguide coupler was fabricated by means of quantum well intermixing. Optical microwave signal was generated in...A new device of two parallel distributed feedback （DFB） lasers integrated monolithically with Y-branch waveguide coupler was fabricated by means of quantum well intermixing. Optical microwave signal was generated in the Y-branch waveguide coupler through frequency beating of the two laser modes coming from two DFB laser in parallel, which had a small difference in frequency. Continuous rapid tuning of optical microwave signal from 13 to 42 GHz were realized by adjusting independently the driving currents injected into the two DFB lasers.展开更多
Using non-identical quantum wells as the active material, a new distributed-feedback laser is fabricated with period varied Bragg grating. The full width at half maximum of I 15 nm is observed in the amplified spontan...Using non-identical quantum wells as the active material, a new distributed-feedback laser is fabricated with period varied Bragg grating. The full width at half maximum of I 15 nm is observed in the amplified spontaneous emission spectrum of this material, which is flatter and wider than that of the identical quantum wells. Two wavelengths of 1.51 μm and 1.53 μm are realized under different work conditions. The side-mode suppression ratios of both wavelengths reach 40 dB. This device can be used as the light source of coarse wavelength division multiplexer communication systems.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 60476009.
文摘Thermal annealing effect on lnAs quantum dots grown on vicinal （100） GaAs substrates is studied in comparison with dots on exact （100） GaAs substrates. We find that annealing acts stronger effect on dots with vicinal substrates by greatly accelerating the degradation of material quality, as well as slightly increasing the blueshift of the emission wavelength and the narrowing of PL linewidth. It is attributed to the higher strain in the dots formed on the vicinal substrates.
基金Project supported by the National Natural Science Foundation of China （Grant No 60476009）.
文摘Self-assembled lnAs quantum dots （QDs） are grown on vicinal GaAs （100） substrates by using metal-organic chemical vapour deposition （MOCVD）. An abnormal temperature dependence of bimodal size distribution of InAs quantum dots is found. As the temperature increases, the density of the small dots grows larger while the density of the large dots turns smaller, which is contrary to the evolution of QDs on exact GaAs （100） substrates. This trend is explained by taking into account the presence of multiatoinic steps on the substrates. The optical properties of InAs QDs on vicinal GaAs（100） substrates are also studied by photoluminescence （PL） . It is found that dots on a vicinal substrate have a longer emission wavelength, a narrower PL line width and a much larger PL intensity.
基金Project supported by the National Natural Science Foundation of China （Grant No 90401025）. Acknowledgments The authors are grateful to the Multiple-function 0ptoelectronic Integration group, Institute of Semiconductors, CAS for sponsoring this project. We extend our thanks to Professor Wang Zi-Yu of Peking University for microwave signal testing.
文摘A new device of two parallel distributed feedback （DFB） lasers integrated monolithically with Y-branch waveguide coupler was fabricated by means of quantum well intermixing. Optical microwave signal was generated in the Y-branch waveguide coupler through frequency beating of the two laser modes coming from two DFB laser in parallel, which had a small difference in frequency. Continuous rapid tuning of optical microwave signal from 13 to 42 GHz were realized by adjusting independently the driving currents injected into the two DFB lasers.
基金Supported by the National Basic Research and Development Programme of China Grant No G20000683-1, the National Natural Science Foundation of China under Grant No 90401025, and the National Hi-Tech Researcn and Development Programme of China under Grant No 2002AA312150.
文摘Using non-identical quantum wells as the active material, a new distributed-feedback laser is fabricated with period varied Bragg grating. The full width at half maximum of I 15 nm is observed in the amplified spontaneous emission spectrum of this material, which is flatter and wider than that of the identical quantum wells. Two wavelengths of 1.51 μm and 1.53 μm are realized under different work conditions. The side-mode suppression ratios of both wavelengths reach 40 dB. This device can be used as the light source of coarse wavelength division multiplexer communication systems.
