A simple method for measurement of the alpha-factor in semiconductor Fabry-Perot lasers operating above threshold

Abstract

A measurement method for the linewidth enhancement factor of a semiconductor Fabry-Perot (FP) laser operating above threshold is presented. This measurement method is designed to have a simple structure and an extend operational range. The active carrier density of the FP laser is modulated by optical injection locking, which makes it possible to measure the variation of optical spectrum from the injected optical frequency.