Gain recovery dynamics in broadband terahertz quantum cascade lasers

摘要

We present the results of our study of the gain recovery time of a broadband heterogeneous (from 2.1 THz and 2.9 THz) terahertz quantum cascade heterostructure (QCH) based on a four-quantum-well resonant phonon extraction design using terahertz time domain spectroscopy. A gain recovery time between 35 ps and 45 ps has been observed in the QCL operating above the lasing threshold.