| 摘要 |
PURPOSE: To provide economically an optical fiber amplifier with high reliability and to adjust independently output levels of plural pieces of optical fiber amplifiers. CONSTITUTION: An incoming amplifier unit 100 and an outgoing amplifier unit 100' are constituted equally. Input light LIN is light amplified by excitation light supplied from an optical multiplexer 105 when it passes through an erbium dope fiber 103 through an optical isolator 101 to be outputted LOUT through the optical isolator 102. The excitation light is supplied from an output port O1 of a 3×2 coupler 10 to the optical multiplexer 105. The 3×2 coupler 110 branches/couples the excitation light from three excitation light sources 1-3 to output them to two output ports, and even when any one excitation light source breaks down, the amplifying power of the optical fiber amplifier is not lost. Further, by adjusting the light emission intensities of respective excitation light sources, the output levels of respective incoming, outgoing optical fiber amplifiers are adjusted independently. |
