Abstract-Ultrafast and nonlinear dynamics of InAs/GaAs semiconductor quantum dot lasers

Frédéric Grillot, D. Arsenijevic, H. Huang,  D. Bimberg,

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10543/105430M/Ultrafast-and-nonlinear-dynamics-of-InAs-GaAs-semiconductor-quantum-dot/10.1117/12.2299678.short

Quantum dot nanostructures are one of the best practical examples of emerging nanotechnologies hence offering superior properties as compared to their quantum well counterparts. InAs/GaAs quantum dots allow producing energy- and cost-efficient devices with outstanding temperature stability, lowest threshold current, ultrafast gain dynamics, and low amplified spontaneous emission. This paper reports on the recent achievements in ultrafast and nonlinear dynamics properties of InAs/GaAs quantum dot lasers for radar systems, wireless communications and high-speed optical communications. Passive mode-locking is shown to exhibit a great potential for microwave, millimeter-wave and Terahertz signal generation with high repetition frequency tuning and jitter reduction. The optical feedback is also used to stabilize the pulse emission leading an integrated timing jitter as low as 90 fs without consuming additional power. Lastly, multimode optical feedback dynamics of InAs/GaAs QD lasers emitting on different lasing states is also studied. In particular, a chaos free operation is observed for the first time from the ground state lasing operation.

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Abstract-Rate equation modeling of the frequency noise and the intrinsic spectral linewidth in quantum cascade lasers

Xing-Guang Wang, Frédéric Grillot, and Cheng Wang

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-3-2325&origin=search

This work theoretically investigates the frequency noise (FN) characteristics of quantum cascade lasers (QCLs) through a three-level rate equation model, which takes into account both the carrier noise and the spontaneous emission noise through the Langevin approach. It is found that the power spectral density of the FN exhibits a broad peak due to the carrier noise induced carrier variation in the upper laser level, which is enhanced by the stimulated emission process. The peak amplitude is strongly dependent on the gain stage number and the linewidth broadening factor. In addition, an analytical formula of the intrinsic spectral linewidth of QCLs is derived based on the FN analysis. It is demonstrated that the laser linewidth can be narrowed by reducing the gain coefficient and/or accelerating the carrier scattering rates of the upper and the lower laser levels.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement