Measurements of chirp and linewidth enhancement factor of DFB semiconductor lasers using a self-homodyne interferometric system

A self-homodyne interferometric optical system fed by a modulated DFB semiconductor laser is used to obtain the AM and FM response, the chirp parameter and the linewidth enhancement factor of these lasers. Three different DFB lasers were measured and the results are in good agreement with those obtained by others techniques. The knowledge of these lasers characteristics are important in high-performance optical communications systems, to improve the FM response, the transmission data rates, predict channel densities and reduce crosstalk.