Abstract

Rare earth-doped fibers are usually inserted in Fabry-Perot resonators yielding highly multimode operation because of both long cavity lengths and large fluorescence spectra.¹ Spectral selectivity can be achieved either by including bulk elements inside the cavity or through the coupling of several cavities (Vernier effect). A new cavity based on this effect has been recently proposed² to obtain single-long itudinal-mode operation.

© 1992 Optical Society of America