The concept of tunneling injection was introduced in the 1990’s to improve the dynamical properties of semiconductor lasers by avoiding the problem of hot carrier injection which increase the gain nonlinearity and hence limit the modulation capabilities. Indeed, tunneling injection led to record modulation speeds in quantum well lasers. Employing tunneling injection in quantum dot lasers is significantly more complicated. Tunneling injection is based on an energy band alignment between a carrier reservoir and the active region where laser oscillation takes place. However, the inherent inhomogeneity of self-assembled quantum dots prevents an unequivocal band alignment and can cause the tunneling injection process to actually deteriorate the laser performance compared to nominally identical quantum dot lasers that have no tunneling section. Understanding the complex process of tunneling injection in quantum dot lasers requires a comprehensive study where different aspects are analyzed theoretically and experimentally. In this paper we describe the technology of such lasers in the InP material system followed by a microscopic analysis of the detailed electrical characterization which is correlated to the electro-optic properties yields information about the exact carrier transport mechanism at bias levels of almost zero to well above threshold. A tunneling injection quantum dot optical amplifier was used for multi wavelength pump probe characterization from which it is clear why tunneling injection often deteriorates laser performance and determines how to design a structure which can take advantage of tunneling injection. Finally, we present a direct comparison between the modulation response of a tunneling injection quantum dot laser and a twin structure that has no tunneling injection section.

The broad study sheds light on the fundamental tunneling injection process that can guide the design of an optimum laser where tunneling injection will be taken full advantage of and will improve the dynamical properties.

隧道注入的概念是在 1990 年代引入的，旨在通过避免热载流子注入问题来改善半导体激光器的动态特性，热载流子注入会增加增益非线性并因此限制调制能力。事实上，隧道注入导致量子阱激光器的调制速度创下纪录。在量子点激光器中采用隧道注入要复杂得多。隧道注入基于载流子储存器和发生激光振荡的有源区之间的能带对齐。然而，自组装量子点固有的不均匀性阻碍了明确的能带对齐，并且与没有隧道部分的名义上相同的量子点激光器相比，可能导致隧道注入过程实际上降低了激光器的性能。理解量子点激光器中隧道注入的复杂过程需要进行全面的研究，从理论上和实验上分析不同方面。在本文中，我们描述了 InP 材料系统中此类激光器的技术，然后对与电光特性相关的详细电学特性进行了微观分析，从而在偏置水平几乎为零到良好的情况下产生了有关准确载流子传输机制的信息高于阈值。隧道注入量子点光放大器用于多波长泵浦探针表征，从中可以清楚为什么隧道注入通常会降低激光性能，并决定了如何设计可以利用隧道注入优势的结构。最后，

广泛的研究揭示了基本的隧道注入过程，可以指导最佳激光器的设计，其中隧道注入将被充分利用并改善动态特性。