Theoretical modeling of quantum dots nanolasers and disordered coupled-cavity arrays [article]

Mawussey Segnon, Universität Bremen, Frank Jahnke
Ultrasmall semiconductor lasers have emerged as strong candidates for the implementation of quantum information processing devices. Manufacturing such nanophotonic light sources heavily relies on the use of cavity quantum electrodynamic effects to enhance spontaneous emission and enable the lasing threshold to be crossed with gain contributions from only a few solid-state emitters. In the cavity quantum electrodynamic regime, the emission dynamics of nanolasers is governed by photonic and
more » ... onic correlation and fluctuations effects. This thesis accompanies some of the advancements in ultrasmall lasers by using microscopic quantum-opticalmodels to enable a better understanding of the underlying physical effects. The frst main topic of this thesis draws on time-resolved photon-correlation spectroscopy to investigate the build up of second-order coherence, associated with lasing, on a different timescale than the emission itself in a quantum-dot photonic-crystal nanolaser emitting in the telecom band. By combining measurements perfomed by Dr. Galan Moody at the National Institute of Standards and Technology, Colorado, USA, with a microscopic semiconductor laser theory, the non-Markovian behavior of the emission dynamics is attributed to carrier-photon correlations that are not amenable by using laser rate-equation formalism. The obtained insights have direct implications with respect to the modulation response, repetition rate, noise characteristics, and coherence properties of nanolasers for device applications. The second main topic concerns a theoretical modeling of single-emitter lasing effects in a quantum dot (QD)-microlaser under controlled variation of background gain provided by off-resonant discrete gain centers. In the framework of a judicious two-color excitation scheme, recently put forward by the group of Prof. Stephan Reitzenstein in Berlin, the background gain contribution of off-resonant QDs can be continuously tuned by precisely balancing the relative excitation power of two lasers emitting at [...]
doi:10.26092/elib/377 fatcat:tv7g5xafjfeohgb2otblk2tkza