The word "quantum" gained currency in the late 20th century as a descriptor signifying something so significant it defied the use of common adjectives.
Harry (1998) defined Six Sigma as a strategic initiative to boost profitability, increase market share and improve customer satisfaction through statistical tools that can lead to breakthrough quantum gains in quality.
Going a bit further, an anisotropic stress applied onto a quantum well gain medium induces polarization dependent variations of both the gain and the refractive index19,20,21, which in turn directly impacts the nonlinear polarization dynamics of the laser itself22.
A quantum efficiency gain of at least 18% can be inferred, from an artifactual test, between textured and flat n-well/p-epi junctions.
Our microscopic, spatially resolved model combines a density matrix description of the optoelectronic properties of quantum well gain media with the full-time-domain Maxwell equations for the electromagnetic (i.e. the coupled electric and magnetic) field dynamics.
The devices consist of an epitaxial GaSb/AlAsSb distributed Bragg reflector (DBR), a GaInAsSb quantum well gain section, a dielectric top DBR and a buried tunnel junction (BTJ) for electrical as well as optical confinement.
We shall discuss the physical principles of ultrashort pulse generation in these lasers, considering in turn the role played by the semiconductor quantum well gain structure, and the saturable absorber.
Meinzer, N. et al. Arrays of Ag split-ring resonators coupled to InGaAs single-quantum-well gain.
Van Der Sande, G., Danckaert, J., Veretennicoff, I., Panajotov, K. & Balle, S. Analytical approximation for the quantum-well gain and refractive-index spectra of vertical-cavity surface-emitting lasers including the effect of uniaxial planar stress.
From a more fundamental point of view, this result also confirms that the chaotic dynamics originates from the VCSEL structure itself and is not related to the quantum dots as gain medium as it could have been mistakenly foreseen from previous observations.
