Abstract

The Er³⁺ doped fiber laser operating at 1.5 μm is interesting for some applications, in particular, for telecommunications. However, previously reported fiber laser cavities were either a Fabry-Perot type with dielectric film mirrors on both ends of the fiber or, for a tunable laser,^1-3 with an external grating as the wavelength tuning element. In both cases, high excess cavity loss was inevitable. Recently, we reported a novel tunable all-fiber ring laser⁴ in which a tunable fiber coupler was used not only for coupling the doped fiber to become a ring cavity but also as a wavelength tuning element. The optimum design of a tunable Er³⁺/Yb³⁺ doped all-fiber ring laser, as shown in Fig. 1, is presented by analyzing the wavelength selectivity of the coupler; the experimental results of the laser are reported.

© 1990 Optical Society of America