Multiple wavelength oscillation at 0.91, 1.08, 1.53, and 1.55 &mgr;m has been simultaneously obtained in a fusion‐spliced silica‐based fiber laser consisting of Er3+‐doped and Nd3+‐doped fibers. The laser mirrors, which are butted against the cleaved fiber ends, have high reflectivities at these wavelengths with a high transmission at a pumping wavelength of 514 nm. The output powers at 0.91, 1.08, and 1.53 &mgr;m are 2.0, 1.7, and 0.42 mW, respectively, for absorbed powers of 115 mW in a Nd3+‐doped fiber and 185 mW in an Er3+‐doped fiber.