| 摘要 |
PROBLEM TO BE SOLVED: To widen the transmission band of an optical amplifier by connecting rare earth doped fibers, where at least one of the kind of rare earth element to be doped or the dose thereof is different, in cascade and employing the cas cade connection as an amplifying medium. SOLUTION: The (n) pieces of rare earth doped fibers (REED fiber) FA1 -FAn of (n) kinds are connected in cascade to produce an amplifying medium. Each REED fiber FAi has such characteristics Gci as the gain is highest at a wavelengthλpi (i represents the i-th fiber among n fibers). More specifically,λpi and Gci are determined by selecting the dose and and/or the kind of rare earth element to be doped appropriately. A plurality of REED fibers having different gain peak characteristics are connected in cascade and employed as an amplifying medium. A pumping light source 6 generates pumping lights corresponding to (n) fibers. |
