Development of device structures with simultaneous optical and electronic confinement and microscopic transmission measurements on their lasing, absorption, and gain characteristics

我们开发了具有光学和电子同步约束的新型器件结构，如量子线激光器，并在我们的微观光传输测量系统的基础上研究了它们的激光，吸收和增益特性。我们首先用有限元方法开发了计算代码，用于设计和优化电子和光子的量子限制结构。我们还开发了测量系统，用于不同温度下的光泵浦激光，俯视图光致发光光谱和图像，以及从波导传输光。对于解理边缘过生长的t型量子线激光结构，研究了过生长表面的界面粗糙度问题，该问题限制了结构的最终质量，并引入了一种新的生长中断退火方法来解决这一问题。我们最终实现了原子平面界面，在横向范围内没有超过几十微米的单层台阶。制备了单模一维量子线和单模一维光波导组合的单量子线激光器。我们在2001年8月第一次观测到它的激光。激光结构包括一维光波导中的二维量子阱和三维双异质结构，以及二维平板光波导中的二维量子阱。也就是说，它包含了2d电子- 1d光子、3d电子- 1d光子、2d电子- 2d光子、2d电子- 2d光子的结构。此外，这些结构都可以产生激光，因此我们可以同时比较所有结构的激光特性。此外，我们还对一维激子和一维连续态的吸收光谱进行了分辨，并首次观测到一维系统固有的Sommerfeld因子。

We develop novel device structures with simultaneous optical and electronic confinement such as quantum wire lasers, and study their lasing, absorption, and gain characteristics on the basis of our microscopic optical transmission measurement systems.We first developed computation codes with the finite element methods for design and optimization of quantum-confined structures for electrons and photons. We also developed measurement systems for optically pumped lasing at various temperatures, top-view photoluminescence spectra and images, and transmission light from waveguides.As for the cleaved-edge overgrown T-shaped quantum wire laser structures, we investigated the problem of interface roughness on (110) overgrowth surfaces, which limit the final quality of the structures, and resolved the problem by introducing a new growth interruption annealing method. We finally realized atomically flat interface without monolayer steps over several tens of micro-meters in lateral extent.A single quantum wire laser, which is a combination of a single-mode 1-D quantum wire and a single-mode 1-D optical waveguide was fabricated. We observed its lasing for the first time in August 2001. The laser structure includes 2-D quantum wells and 3-D double-hetero-structures in the 1-D optical waveguide and a 2-D quantum well in a 2-D slab optical waveguide. In other words, it contains structures of 1D-electron-1D-photon together with 2D-electron- 1D-photon, 3D-electron-1D-photon, and 2D-electron- 2D-phbton. Furthermore, these structures all make lasing, so that we can compare lasing characteristics of all the structure simultaneously. In addition, we resolved absorption spectra of 1-D excitons and 1-D continuum states, and observed the Sommerfeld factor inherent to 1-D systems for the first time.