Theory of gain, modulation response, and spectral linewidth in AlGaAs quantum well lasers

We investigate theoretically a number of important issues related to the performance of AlGaAs quantum well (QW) semiconductor lasers. These include a basic derivation of the laser gain, the linewidth enhancement factor α, and the differential gain constant in single and multiple QW structures. The results reveal the existence of gain saturation with current in structures with a small number of wells. They also point to a possible two-fold increase in modulation bandwidth and a ten-fold decrease in the spectral laser linewidth in a thin QW laser compared to a conventional double heterostructure laser

Quantum well lasers -- Gain, spectra, dynamics

We discuss a number of theoretical and experimental issues in quantum well lasers with emphasis on the basic behavior of the gain, the field spectrum, and the modulation dynamics. It is revealed that the use of quantum well structures results in improvement of these properties and brings several new concepts to optical semiconductor devices

Quantum noise and dynamics in quantum well and quantum wire lasers

We calculate the relaxation oscillation corner frequency fr and the linewidth enhancement factor alpha for both a quantum well and a quantum wire semiconductor laser. A comparison of the results to those of a conventional double heterostructure device indicates that fr can be enhanced by 2× in the quantum well case and 3× in the quantum wire case while alpha is reduced in both cases

Reduction of the field spectrum linewidth of a multiple quantum well laser in a high magnetic field—spectral properties of quantum dot lasers

The field spectrum linewidth of a multiple quantum well laser immersed in a high magnetic field is measured at room temperature and at 165 K. The low-temperature measurements show a decrease of linewidth with increasing magnetic field. We believe this behavior results from the formation of a totally discrete electronic state space. Measurements of the low-temperature luminescence spectrum show that the emission is split into two peaks by the high field with the higher energy peak responsible for lasing action