<title>Small-signal intensity modulation response of a single-quantum-well laser</title>

Abstract

A new model for the small signal intensity modulation response is described which utilizes a new analytic description of the quantum well laser based on the concept of a stimulated lifetime. The new analysis is able to qualitatively predict the modulation response of quantum well lasers without the concept of non-linear gain. The analysis uses the quasi-Fermi level separation as a parametric variable to couple the electron and photon rate equations. In particular, the Fermi level allows the effects of the diode losses to be an integral part of the small signal transfer function. It is shown that by including all the current components in the electron rate equation, the modulation response of the laser is fundamentally limited by the diode carrier lifetime. This is a consequence of the less than unity value of the electrical confinement factor within the quantum well. The recombination and diffusion current components outside the well are shown to be the cause of the increased damping of the laser resonance as the bias applied to the laser is increased.