| 摘要 |
PURPOSE:To increase the number of information sources which can be connected by connecting single-mode optical fibers which have >=0.6mum and no polarization dependency. CONSTITUTION:Optical fibers 10a and 10b consist of, for example, the single- mode optical fibers which have no polarization dependency, >=0.6mum cutoff wavelength, and zero-dispersion wavelength of about 1.5mum as well as an optical fiber 5 for a transmission line, and the optical fiber 10b is connected to the multiplexed light projection side of an optical coupler 8 and the input side of an optical fiber amplifier 9. Thus, exciting light is multiplexed with only the light signal of an information source 3 to be selected and made incident on the connected optical fiber amplifier 9; and the exciting light is not coupled with light signals of remaining unselected information sources 3 and only the light signals are made incident on optical fiber amplifiers 9. Consequently, only desired information can be obtained without controlling the information source directly. The optical branching loss of the optical couplers 2 can be compensated. Consequently, the number of information sources which can be connected can be increased. |
