Density-Matrix Model for Photon-Driven Transport in Quantum Cascade Lasers

Soleimanikahnoj, S.; King, Michelle; Knežević, I.

doi:10.1103/physrevapplied.15.034045

Cited by 3 publications

(1 citation statement)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A threeband k • p model is used to account for the nonparabolicity in the band structure. This work was extended to study photon-assisted electron transport [377].…”

Section: Quantum Cascade Devicesmentioning

confidence: 99%

Computational perspective on recent advances in quantum electronics: from electron quantum optics to nanoelectronic devices and systems

Weinbub

Kosik

2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Quantum electronics has significantly evolved over the last decades. Where initially the clear focus was on light-matter interactions, nowadays approaches based on the electron's wave nature have solidified themselves as additional focus areas. This development is largely driven by continuous advances in electron quantum optics, electron based quantum information processing, electronic materials, and nanoelectronic devices and systems. The pace of research in all of these areas is astonishing and is accompanied by substantial theoretical and experimental advancements. What is particularly exciting is the fact that the computational methods, together with broadly available large-scale computing resources, have matured to such a degree so as to be essential enabling technologies themselves. These methods allow to predict, analyze, and design not only individual physical processes but also entire devices and systems, which would otherwise be very challenging or sometimes even out of reach with conventional experimental capabilities. This review is thus a testament to the increasingly towering importance of computational methods for advancing the expanding field of quantum electronics. To that end, computational aspects of a representative selection of recent research in quantum electronics are highlighted where a major focus is on the electron's wave nature. By categorizing the research into concrete technological applications, researchers and engineers will be able to use this review as a source for inspiration regarding problem-specific computational methods.

show abstract

“…A threeband k • p model is used to account for the nonparabolicity in the band structure. This work was extended to study photon-assisted electron transport [377].…”

Section: Quantum Cascade Devicesmentioning

confidence: 99%

Computational perspective on recent advances in quantum electronics: from electron quantum optics to nanoelectronic devices and systems

Weinbub

Kosik

2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

Nonlinear gain models in a quantum cascade laser

Kolek,

Sobaszek

2023

Opt. Express

View full text Add to dashboard Cite

Density matrix analysis of a three-state model of quantum cascade laser (QCL) reveals that in this device, the optical gain is composed of the linear part (proportional to population inversion Δn) and the remaining nonlinear part. The nonlinear component non-negligibly contributes even to the small-signal response of the medium. In many attempts to modeling QCLs, the common practice to account for nonlinear gain components is to complement the equation for the gain, g = g c Δn, g c is the gain cross-section, by a compression factor f. In this paper, improved (but still simple) models of the optical gain in QCL are proposed, which preserve the two-component gain structure. With these models, there is no need to solve the Hamiltonian with time-dependent potentials, so that extraordinary numerical loads can be avoided, but simultaneously the essential physics of the phenomena is kept. The improved gain models defined by Eqs. (12), (15) and (16) enable accounting for its nonlinear components while preserving the load-saving, scattering-like approach to light-matter interaction. It is also shown that as long as the populations and dc coherences are determined such that they account for the interaction with the optical field, the small-signal formulation of the gain gives its realistic estimate also for a large optical signal. This conjecture validates the use of non-equilibrium Green’s function-based approaches, in which the interaction with the optical field is included through electron-photon selfenergies. The small-signal formulation of the gain can be used in this approach to monitor the saturation process, estimate the clamping flux and the light-current characteristic.

show abstract

Modeling with graded interfaces: Tool for understanding and designing record-high power and efficiency mid-infrared quantum cascade lasers

Suri,

Knipfer,

Grange

et al. 2024

Nanophotonics

View full text Add to dashboard Cite

By employing a graded-interfaces model based on a generalized formalism for interface-roughness (IFR) scattering that was modified for mid-infrared emitting quantum cascade lasers (QCLs), we have accurately reproduced the electro-optical characteristics of published record-performance 4.9 µm- and 8.3 µm-emitting QCLs. The IFR-scattering parameters at various interfaces were obtained from measured values and trends found via atom-probe tomography analysis of one of our 4.6 μm-emitting QCL structures with variable barrier heights. Those values and trends, when used for designing a graded-interface, 4.6 μm-emitting QCL, led to experimental device characteristics in very good agreement with calculated ones. We find that the published record-high performance values are mainly due to both injection from a prior-stage low-energy (active-region) state directly into the upper-laser (ul) level, thus at low field-strength values, as well as to strong photon-induced carrier transport. However, the normalized leakage-current density J leak /J is found to be quite high: 26–28 % and 23.3 %, respectively, mainly because of IFR-triggered shunt-type leakage through high-energy active-region states, in the presence of high average electron temperatures in the ul laser level and an energy state adjacent to it: 1060 K and 466 K for 4.9 µm- and 8.3 µm-emitting QCLs, respectively. Then, modeling with graded interfaces becomes a tool for designing devices of performances superior to the best reported to date, thus closing in on fundamental limits. The model is employed to design a graded-interface 8.1 µm-emitting QCL with suppressed carrier leakage via conduction-band engineering, which reaches a maximum front-facet wall-plug efficiency value of 22.2 %, significantly higher than the current record (17 %); thus, a value close to the fundamental front-facet, upper limit (i.e., 25 %) for ∼8 µm-emitting QCLs.

show abstract

Density-Matrix Model for Photon-Driven Transport in Quantum Cascade Lasers

Cited by 3 publications

References 31 publications

Computational perspective on recent advances in quantum electronics: from electron quantum optics to nanoelectronic devices and systems

Computational perspective on recent advances in quantum electronics: from electron quantum optics to nanoelectronic devices and systems

Nonlinear gain models in a quantum cascade laser

Modeling with graded interfaces: Tool for understanding and designing record-high power and efficiency mid-infrared quantum cascade lasers

Contact Info

Product

Resources

About