Patent ID: 8325330

Claim:
A remote fiber test system comprising: a first optical fiber line having two ends; a plurality of second optical fiber lines each having two ends; a branch-type optical fiber line including a first optical splitter connecting a first end of the first optical fiber line to a first end of each of the plurality of second optical fiber lines; and test equipment connected to a second end of the first optical fiber line, the test equipment comprising a light source, a second optical splitter, a detecting part, a control unit, and a probe light gate that receives probe light output from the second optical splitter and outputs the probe light selectively during a period of first gate width w 1 at a constant period T, wherein the light source outputs light having a comb-shaped optical coherence function formed by means of modulation of optical frequency by a modulation signal of period p, and the second optical splitter receives light output from the light source and outputs the light, splitting into probe light and reference light, and the detecting part detects interference light and converts the interference light into an electrical signal so as to output, the interference light occurring from mutual interference between reflected light and reference light, the reflected light arising while the probe light output from the second optical splitter propagates through the branch-type optical fiber line, the reference light being output from the second optical splitter, and the control unit changes the period p and, on the basis of the period p and the electrical signal output from the detecting part, obtains reflectance distribution along the direction of the probe light propagation in the branch-type optical fiber line, and wherein the detecting part outputs electrical signals corresponding to the intensity of interference light arising from mutual interference between reflected light and reference light selectively during a period of second gate width w 2 at the constant period T through a specific frequency band, the reflected light occurring when the probe light output from the probe light gate propagates through the optical fiber line, the reference light being output from the second optical splitter.