Open AccessMicroscopic mechanism underlying double-state lasing in an InAs/GaAs quantum dot laser diode elucidated using coupled rate equations and the spontaneous emission recorded from a window structure
Author(s) -
J. M. Lee,
Byeong Hwa Jeon,
J. Kim,
D. Lee
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.031682
Subject(s) - lasing threshold , gain switching , excited state , laser , quantum dot , spontaneous emission , diode , quantum dot laser , rate equation , semiconductor laser theory , optoelectronics , materials science , atomic physics , laser diode , physics , optics , quantum mechanics , kinetics
We investigated the microscopic mechanism underlying the double-state lasing behavior (simultaneous lasing at the ground state [GS] and excited state [ES]) in InAs/GaAs quantum dot (QD) laser diodes. The ES and GS lasing processes that contributed to double-state lasing were examined experimentally and theoretically. Experiments were conducted in which spontaneous emission from a window of a QD laser diode was examined under lasing conditions, and numerical simulations were performed using a coupled rate equation model of the QD microstates. The findings showed that, when carrier relaxation from the ES to the GS was sufficiently slow, double-state lasing occurred. Additionally, ES lasing was found to arise not from the QD group undergoing GS lasing, but rather from another QD group in which the states were lower in energy and outside of the homogeneous bandwidth.