Open AccessFrequency noise analysis of 1.55 µm indium arsenide/indium phosphide quantum dot lasers: impact of non‐linear gain and direct carrier transition
Author(s) -
Sanaee Maryam,
Zarifkar Abbas,
Sheikhi Mohammad Hossein
Publication year - 2016
Publication title -
iet optoelectronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.379
H-Index - 42
eISSN - 1751-8776
pISSN - 1751-8768
DOI - 10.1049/iet-opt.2015.0027
Subject(s) - lasing threshold , wetting layer , quantum dot , quantum dot laser , laser , indium phosphide , laser linewidth , semiconductor laser theory , noise (video) , rate equation , ground state , materials science , physics , gallium arsenide , optoelectronics , atomic physics , optics , quantum mechanics , artificial intelligence , computer science , kinetics , image (mathematics)
Frequency noise (FN) characteristic of 1.55 µm quantum dot (QD) lasers is investigated by introducing a theoretical model. A set of five rate equations are developed in presence of Langevin noise sources by writing a new equation for dynamics of the optical field phase. To investigate the effects of non‐linear gain and direct carrier transition on FN spectrum of QD lasers, the auto and cross‐correlation coefficients between carriers and photons have been calculated. Calculations demonstrate that the excited state and ground state (GS) carriers’ shot noises play dominant role on both the level and the resonance frequency of FN spectrum. Moreover, the level of FN declines by increasing the non‐linear gain coefficient. On the other hand, direct carrier transition from wetting layer to the lasing state of GS leads to lower‐frequency fluctuations. Finally, it is revealed that the linewidth of QD laser decreases by increasing the pumping current and its value is in the order of about 1 MHz.