The linewidth enhancement factor α is known to have an important impact on semiconductor laser frequency stability. We determine under what general circumstances the value of α for a semiconductor laser may depend upon the longitudinal laser structure. A longitudinal modulation of the modal refractive index is shown not to have any influence on α, while our results indicate that a longitudinal modulation of the modal gain such as would be used in a gain-coupled laser will in general change the linewidth enhancement factor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.