| 摘要 |
An input lightwave signal enters a Wavelenght Demultiple Multiple (WDM) coupler (2) via an optical circulator (1). To the WDM coupler (2), an excited light beam emitted from an excitation LD (3) which is driven by an excitation LD driving circuit (4) is entered. The WDM coupler (2) combines the input lightwave signal with the excited light beam, and leads it to an erbium-doped fiber (EDF)(5). The EDF (5) amplifies the lightwave signal incident from the WDM coupler (2). The amplified signal is led to a total reflector (6). The signal entered into the total reflector (6) is reflected and reentered into the EDF (5) to be amplified again. Then, the signal goes out through the WDM coupler (2) and optical circulator (1). <IMAGE> |
