Abstract

For much of this decade, interest has been sustained in developing high performance single frequency Er³⁺-fiber lasers¹-³. For robust single frequency operation, these lasers need to be only centimeters long. Early grating-based fiber lasers relied on Er-germanosilicate fibers, but lasing powers were low - μW typically¹,², due to low pump absorption in the short cavity. Increasing the Er-concentration to increase absorption is however difficult. Germanosilicate fibers are prone to ion clustering, which degrades the efficiency and destablises⁴,⁵ the laser. Thus the need to amplify the laser power to useful levels of a mW or more is a drawback where low noise sources are desired.

© 1997 Optical Society of America