Abstract

There is considerable interest in the development of Er-doped fiber lasers for communication and sensor applications. The unidirectional ring-cavity configuration can provide narrow- linewidth, tunable single-frequency sources for wavelengths between 1520 and 1560 nm in a compact all-fiber form.^1-4 Recently, a ring laser with two intracavity Fabry-Perot (FP) filters¹ with good single-frequency operation and wide tunability was reported. A problem with this configuration is the relatively large insertion loss associated with the FP filters (typically ~3 dB/ filter). In this paper we describe ring-laser configurations, shown in Fig. 1, that accomplish a similar type of wavelength selection with a single intracavity filter element.

© 1993 Optical Society of America