A rare-earth doped optical fiber module including a resin reel having elasticity
and a rare-earth doped optical fiber wound around the resin reel. The rare-earth
doped optical fiber module further includes a single-mode optical fiber spliced
to the rare-earth doped optical fiber and wound around the resin reel. The resin
reel is formed of silicone rubber, fluororubber, or soft PVC.