Optical gain beyond Hakki-Paoli. a new power tool for reliability of laser diodes

Simpler procedures for gain measurements in commercial laser diodes are introduced. They fully agree with the results of the popular Hakki-Paoli method, greatly extend its application range and remove those practical constraints that reserve practical gain measurement to the sole device designer and manufacturer. The aim of the paper is to propose the new method for reliability studies, to support and address the investigation of Failure Physics of semiconductor lasers. Some recent puzzling case histories are also summarized, that did not benefit of the new method. Their role is to point out how many unsuspected, and even unexplained physical phenomena may affect a technology that is not yet really assessed.