On formula for natural linewidth in distributed feedback lasers; simulation of experiments

Formulas for natural linewidth in dimensional and non-dimensional forms for distributed feedback (DFB) lasers are derived on the basis of the formula for the line shape which has been derived in the process of applying effective nonlinear photorefractivity which is assumed. Corrugation, phase, and amplitude components of the natural linewidth are taken into account. We have defined characteristic parameters describing the natural linewidth of DFB lasers and found their numerical values by solving an inverse problem, and then have simulated experimental measurements represented in the literature. This development brings the subject of understanding and capability of calculating laser parameters, as well as simulating the natural linewidth of semiconductor lasers to a qualitatively new level.