International audienceWithin the framework of a laser guide star and in order to solve the major problem of saturation of the sodium atom, we present an ``all-optical'' modeless laser that excites all sodium velocity classes. A theoretical and experimental study of the excitation of the sodium D2 line is presented in three cases: a single-mode laser of linewidth 1 MHz and modeless lasers of linewidths 3 and 4.5 GHz. The best result is obtained when the linewidth matches the Doppler-hyperfine sodium D2-line profile. By comparison with a single-mode laser excitation, we show that our modeless-laser sodium D2 star becomes six times brighter
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.