| 摘要 |
PURPOSE:To specify the fault point of a line by providing optical parts at respective optical fiber lines so as to reflect light with a wavelength lambdai and to transmit light with wavelengths lambdao and lambdaj ((j) is integers to N, jnot equal to i). CONSTITUTION:The light with a wavelength lambda0 and the light with wavelength lambda1 is made incident to an optical fiber line I1, and the light with the wavelength lambda0 and the light with a wavelength lambda2 is made incident to an optical fiber line I2. The light with the wavelength lambda0 is light for communication, and the light with wavelengths, lambda1, lambda2...lambdai, lambdaj and lambdam is light for monitor so as to searching any fault. When a test wavelength is scanned within a range including these wavelengths in the case of moving a testing device OTDR installed at a station, the reflected light of lambda1, lambda2...lambdan reflected at optical parts D1, D2...Dn arranged at lines I1, I2...In is received from those lines. When any fault point exists at the line I1, the fault point can be specified since the OTDR observes any loss change in the reflected light with the wavelength lambda1. |
