Gain Recovery Dynamics and Photon-Driven Transport in Quantum Cascade Lasers

作     者：Hyunyong Choi Laurent Diehl Zong-Kwei Wu Marcella Giovannini Jérôme Faist Federico Capasso Theodore B. Norris 

作者机构：Center for Ultrafast Optical Science and Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor Michigan 48109-2099 USA School of Engineering and Applied Sciences Harvard University Cambridge Massachusetts 02138 USA Institute of Physics University of Neuchâtel CH-2000 Neuchâtel Switzerland 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2008年第100卷第16期

页      面：167401-167401页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：.intracavity cavity photon gain recovery upper lasing superlattice transport 

摘      要：Quantum cascade lasers are semiconductor devices based on the interplay of perpendicular transport through the heterostructure and the intracavity lasing field. We employ femtosecond time-resolved pump-probe measurements to investigate the nature of the transport through the laser structure via the dynamics of the gain. The gain recovery is determined by the time-dependent transport of electrons through both the active regions and the superlattice regions connecting them. As the laser approaches and exceeds threshold, the component of the gain recovery due to the nonzero lifetime of the upper lasing state in the active region shows a dramatic reduction due to the onset of quantum stimulated emission; the drift of the electrons is thus driven by the cavity photon density. The gain recovery is qualitatively different from that in conventional lasers due to the superlattice transport in the cascade.