Patent ID: 6867910

Claim:
A wideband ASE light source comprising: a pumping light source that generates a pumping light; an erbium-doped optical fiber that generates an ASE light upon receiving the pumping light incident on its one terminal portion; reflecting means that is arranged at the other terminal portion of the erbium-doped optical fiber and reflects partially or totally the ASE light radiated from the erbium-doped optical fiber; an optical multiplexer provided with a first terminal portion connected to the one terminal portion of the erbium-doped optical fiber and a second terminal portion connected to the pumping light source, the optical multiplexer being provided with a third terminal portion and functioning to multiplex and demultiplex the pumping light with or from the ASE light; and an optical isolator that is arranged between, a third terminal portion of the optical multiplexer and an output terminal and removes a return Light to the erbium-doped optical fiber, the optical multiplexer having a maximum value of isolation in a wavelength band of 1570 nm to 1600 nm.