| 摘要 |
PROBLEM TO BE SOLVED: To reduce deterioration in relative intensity noise(RIN), without causing increase in cost, even when an optical fiber for dispersion compensation having a relative index difference which is different from that of a normally used optical fiber is connected, in an optical amplifier having an amplifying optical fiber for directly amplifying a signal light, on the basis of the induced emission effect. SOLUTION: In a light amplifier 1 in which an optical fiber 10 for dispersion compensation is provided, via an isolator 6 on an emission side of a signal light of an amplifying optical fiber 2, an optical fiber for coupling 9f of the isolator 6 and the optical fiber 10 are connected by fusion splicing, and the isolator 6 has its extinction ration set within a range of 40-50dB. |
