【摘 要】
：
Measurements of the excitation power-dependence and temperature-dependence photoluminescence (PL) are performed to investigate the emission mechanisms of InGaN/GaN quantum wells (QWs) in laser diode structures. The PL spectral peak is blueshifted with inc
【机 构】
：
StateKeyLaboratoryforArtificialMicrostructureandMesoscopicPhysicsandSchoolofPhysics,PekingUniversity
【出 处】
：
ChineseOpticsLetters
论文部分内容阅读
Measurements of the excitation power-dependence and temperature-dependence photoluminescence (PL) are performed to investigate the emission mechanisms of InGaN/GaN quantum wells (QWs) in laser diode structures. The PL spectral peak is blueshifted with increasing temperature over a certain temperature range. It is found that the blueshift range was larger when the PL excitation power is smaller. This particular behavior indicates that carriers are thermally activated from localized states and partially screen the piezoelectric field present in the QWs. The small blueshift range corresponds to a weak quantum-confined Stark effect (QCSE) and a relatively high internal quantum efficiency (IQE) of the QWs.
其他文献
In this work two different fluorochromes (Alexa 594 and Alexa 680) are conjugated to the same monoclonal antibody (Cetuximab) for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab by mixing both fluorochromes before the co
An all-fiber regenerative amplifier at 1053 nm is demonstrated. The input signal pulse energy is 75 pJ in a 3.5-ns pulse at a 1-Hz repetition rate. At a low level ofinput pump power of 110 mW, the saturated output energy is 120 nJ with fluctuation less th
We introduce a novel network-coding scheme that can be implemented in all-optical multicast networks. A simple and successful module based on the all-optical XOR gate is designed to realize the network coding scheme. The module is a key hardware component
比较介绍了相机用传统CCD和超级CCD SR的原理, 该超级CCD SR由面积较大、感光度高的“S像素”和为拓宽动态范围而特设的小面积“R像素”组成。实验以基于超级CCD SR的富士F100fd为信号采集器件, 对圆孔的夫琅禾费衍射图像进行采集, 最终的图像能够保证暗处正常表现的情况下噪声控制理想, 同时高亮度的部分没有溢出。实验数据表明, 与普通CCD相比动态范围可拓宽到约4倍, 验证了器件设计的合理性和有效性。
为了实时得到低维材料的应变,提出了一种基于数字图像跟踪的低维材料实时应变测量方法。首先,将试件上制作的标志点或试件表面适当的特征点作为跟踪目标,采用改进的适于跟踪测量的图像相关公式,以及根据低维材料变形特点选取相应的匹配模板和搜索区域,实现了实时测量应变所需的两点跟踪;利用双线性插值算法将目标定位在0.01 pixel上的位置,提高了该方法的测量精度。然后分级施加荷载,不仅实时跟踪到目标,而且得到低维材料在相应载荷下的实时应变值,为研究低维材料动态力学特性提供了一种实验方法。通过实验,验证了数字图像跟踪技
Long-period gratings (LPGs) are fabricated in a photonic crystal fiber (PCF) using the symmetric point-by-point C
In this paper, a temperature sensor based on the splicing of a core offset multi-mode fiber with two single mode fibers is proposed and demonstrated experimentally. The temperature sensing principle is analyzed and related experiment is performed. By cont
Due to its ability of optical sectioning and low phototoxicity,
提出了用双色光子存储来测量寿命的新方法:逐渐延长关闭预激发光与打开写入光束的时间间隔，通过分析衍射信号的变化得到相关能级的寿命。用此方法测得偶氮分子甲基橙和乙基橙的亚稳态寿命分别为4 s和2.7 s。
设计并制备了大功率高光束质量的1060 nm 波长的非对称波导半导体激光二极管.本激光二极管包含压应变InGaAs/GaAs双量子阱和GaAs/AlGaAs分别限制结构。为提高激光二极管的大功率性能，设计激光器二极管的垂直结构具有小快轴远场发散角，大光斑面积及低腔面光能密度，低光腔内吸收损耗和高内量子效率等性能。通过引入4 μm厚弱光限制Al0.1Ga0.9As波导，激光器二极管的远场发散角降到20°，光斑宽度增到接近1 μm。量子阱位置偏调后得到的薄上波导层非对称波导结构可以使激光二极管即使在大电流注入