| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an excitation light source using Raman amplification and an optical fiber communication system by which the insertion loss can be reduced without necessity of a polarized wave multiplexer, which can be economical and high-performance and by which switching from the system actually used to a space system can be performed speedily when an interruption occurs. SOLUTION: In the excitation light source 5, a plurality of lasers 11s, 12p, 17s and 18p output a plural beams of excitation light of different wavelengthsλp1,λp1*,λp2, andλp2* in such a way that the wavelengths of two of the excitation light beams are set close to each other:λp1 andλp1*, andλp2 andλp2*,the state of wave polarization of the two excitation light beams of close wavelengths is set perpendicular to each other, and the plurality of excitation light beams are multiplexed by a multiplexer 61 of wavelength selecting type.</p> |
