| 摘要 |
PURPOSE:To provide a light amplifier which can suppress SN deterioration in the light WDM communication or light analog communication due to the difference in amplification factor or the composite secondary distortion resulting from lesser wavelength dependency of the amplification factor. CONSTITUTION:A light signal fed from an input port 105 is light amplified when it passes through an Er-added optical fiber 21 for amplification. The amplified light signal is passed through an Er-added optical fiber absorbent 131 to undergo an amplification factor correction. The wavelength transmission characteristics of the Er-added optical fiber absorbent 131 can be controlled to any desired value by a control light introduced from a control light source 133. Besides the absorbent 131 as described, correction of the amplification factor can be done even with a dielectric substance multi-layer film filter. Similar correction of amplification factor can be obtained even by introducing control light with the wavelength and output controlled to the Er-added optical fiber for amplification 21. |
