BRANCH OPTICAL LINE CHECKING DEVICE

摘要

PROBLEM TO BE SOLVED: To test each optical branch fiber individually even when drift occurs in a test channel by measuring Rayleigh back scattering light from a branch optical fiber or wavelength of maximum intensity of reflected light from an optical filter. SOLUTION: A variable wavelength light source 9 which has received control of a main control/identifying part 13 outputs pulse testing light, changing test wavelength with a notch that is smaller than the half of full width at half maximum of a test channel, and the part 13 identifies the maximum intensity of returned light from a brand optical fiber which is measured by a photodetector 11. The part 13 calculates a drift amount from the difference between the wavelength of the maximum intensity and the reference wavelength of a wavelength selective optical branch device which is preliminarily acquired as an initial condition in an optical pulse testing device 6. Thereby, it is possible to estimate the maximum transparent wavelength of each test channel by adding correctionally the drift amount to the initial condition of each test channel even to the test channel of the wavelength selective optical branch device under an optional temperature environment.