The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxat...The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxation oscillation frequency of over 30GHz MQW DFB laser is presented.展开更多
分析了梯度折射率分别限制单量子阱 (GRIN-SCH-SQW)结构的特点以及对大功率半导体激光器特性的影响。利用分子束外延系统生长 Ga Al As/Ga As GRIN-SCH-SQW结构 ,经光荧光谱、X-射线双晶衍射、和载流子浓度测试 ,结果表明 ,该结构各参...分析了梯度折射率分别限制单量子阱 (GRIN-SCH-SQW)结构的特点以及对大功率半导体激光器特性的影响。利用分子束外延系统生长 Ga Al As/Ga As GRIN-SCH-SQW结构 ,经光荧光谱、X-射线双晶衍射、和载流子浓度测试 ,结果表明 ,该结构各参数均满足设计要求。应用此结构制成激光器阵列 ,室温准连续输出功率达5 8W(t=2 0 0 μs,f=5 0 Hz) ,峰值波长为 80 8nm。展开更多
The relationship between gain and carrier density is analysed. In the quantum well (QW) lasers, initially, the gain increases rapidly with the carrier density and then starts to saturate. It can be seen that QW lasers...The relationship between gain and carrier density is analysed. In the quantum well (QW) lasers, initially, the gain increases rapidly with the carrier density and then starts to saturate. It can be seen that QW lasers have a higher differential gain because of the step-like state density, and that the gain saturates at higher carrier densities because of the constant state density of the lowest subband. It is shown that simple logarithmic gain-carrier density is more accurate than the traditional linearized form for a QW laser.展开更多
New multi-color photometric observations of the previously unstudied contact binary QW Gem are presented. Completely covered BVR1 band light curves were obtained, including four new times of light minima. The light cu...New multi-color photometric observations of the previously unstudied contact binary QW Gem are presented. Completely covered BVR1 band light curves were obtained, including four new times of light minima. The light curves were simultaneously analyzed with the 2013 version of the Wilson-Devinney method, assuming a third light. The photometric solutions confirm that QW Gem is a W-type W UMa system with a fill-out factor of f - 17%. The absolute parameters of the components were determined to be Mp = 1.33 4- 0.03 Me, Ms = 0.44±0.01Me, Rp = 1.25±0.01Re, Rs = 0.77± 0.01R⊙, Lp = 1.68±0.03L⊙ and Ls = 0.68±0.01L⊙. The orbital period change of QW Gem was investigated by the O-C method using all available data. The results show that this binary system could have undergone a continuous orbital period decrease during the past two decades at a rate of about dP/dt = -2.55×10^-7 d yr^-1. In addition, a small-amplitude oscillation was detected to be superimposed on a long-term decrease.展开更多
文摘The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxation oscillation frequency of over 30GHz MQW DFB laser is presented.
文摘The relationship between gain and carrier density is analysed. In the quantum well (QW) lasers, initially, the gain increases rapidly with the carrier density and then starts to saturate. It can be seen that QW lasers have a higher differential gain because of the step-like state density, and that the gain saturates at higher carrier densities because of the constant state density of the lowest subband. It is shown that simple logarithmic gain-carrier density is more accurate than the traditional linearized form for a QW laser.
基金supported by the Meritocracy Research Funds of China West Normal Universitythe Fundamental Research Funds of China West Normal University
文摘New multi-color photometric observations of the previously unstudied contact binary QW Gem are presented. Completely covered BVR1 band light curves were obtained, including four new times of light minima. The light curves were simultaneously analyzed with the 2013 version of the Wilson-Devinney method, assuming a third light. The photometric solutions confirm that QW Gem is a W-type W UMa system with a fill-out factor of f - 17%. The absolute parameters of the components were determined to be Mp = 1.33 4- 0.03 Me, Ms = 0.44±0.01Me, Rp = 1.25±0.01Re, Rs = 0.77± 0.01R⊙, Lp = 1.68±0.03L⊙ and Ls = 0.68±0.01L⊙. The orbital period change of QW Gem was investigated by the O-C method using all available data. The results show that this binary system could have undergone a continuous orbital period decrease during the past two decades at a rate of about dP/dt = -2.55×10^-7 d yr^-1. In addition, a small-amplitude oscillation was detected to be superimposed on a long-term decrease.
