Pflügl Christian, Diehl Laurent, Lyakh Arkadiy, Wang Qi Jie, Maulini Richard, Tsekoun Alexei, Patel C Kumar N, Wang Xiaojun, Capasso Federico
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
Opt Express. 2010 Jan 18;18(2):746-53. doi: 10.1364/OE.18.000746.
We present a method to study current paths through quantum cascade lasers (QCLs). The temperature dependence of the current is measured at a fixed voltage. At low temperatures we find activation energies that correspond to the energy difference between the injector ground state and the upper laser level. At higher temperatures additional paths with larger activation energies are found. Application of this method to high performance QCLs based on strained InGaAs/InAlAs quantum wells and barriers with different band-offsets allows us to identify individual parasitic current paths through the devices. The results give insight into the transport properties of quantum cascade lasers thus providing a useful tool for device optimization.
我们提出了一种研究通过量子级联激光器（QCL）的电流路径的方法。在固定电压下测量电流的温度依赖性。在低温下，我们发现激活能对应于注入器基态与上激光能级之间的能量差。在较高温度下，发现了具有更大激活能的其他路径。将该方法应用于基于具有不同带隙偏移的应变InGaAs/InAlAs量子阱和势垒的高性能QCL，使我们能够识别通过器件的各个寄生电流路径。这些结果深入了解了量子级联激光器的传输特性，从而为器件优化提供了一个有用的工具。
