Scanning photoluminescence technique to determine the phase of the grating at the facets of gain-coupled DFB's

We demonstrate a rapid, nondestructive scanning photoluminescence (PL) technique for the determination of the phase of the grating at the cleaved or coated facets of "in-phase" gain-coupled distributed feedback lasers. The measured phases of the grating at the cleaved facets of a bar of lasers are found to be consistent with experimental measurements of laser performance.