Fourfold output power enhancement and threshold reduction through thermal effects in Er/sup 3+//Yb/sup 3+/-doped fiber laser

Summary form only given. High power Er/sup 3+/-doped fiber sources either narrow or broadband operating around 1.5 /spl mu/m are very desirable owing to their use in a wide variety of applications including optical communications, sensing, imaging, and spectroscopy. The output efficiency of such sources is substantially improved by employing Er/sup 3+/-doped fiber materials sensitized with Yb/sup 3+/ ions. Using such approach, a 1.0 W superfluorescent Er/Yb-doped fiber source around 1.54 /spl mu/m pumped at 1.054 /spl mu/m was demonstrated. In this work we show that, utilizing the multiphonon-assisted sideband excitation process for the sensitizer, one obtains a fourfold output power enhancement and threshold reduction by heating the Er/Yb-doped medium.