Scanning photoluminescence technique to determine the phase of the grating at the facets of gain-coupled DFBs

The spatial phase of the grating at the partially reflective facet(s) of distributed feedback lasers (DFBs) has a profound effect on the static and dynamic laser performance characteristics. This paper, demonstrates a rapid, nondestructive, and noninvasive scanning photoluminescence (PL) technique for the determination of the phase of the grating at the cleaved or coated facets of 'in-phase' gain-coupled (GC) DFBs. The scanning PL technique provides an important experimental tool for the correlation between DFB performance and simulations using computer models.