PURPOSE: To concurrently measure the distribution of multiple reflection by feeding one branch light branched from the outgoing light into light guide paths to be tested, synthesizing the generated reflected light with the other branch light, and detecting the intensity of the synthesized light.
CONSTITUTION: A photo-coupler 12 used as an optical means branches the outgoing light of a light source 1, one branch light is fed to light guide paths 26-30 to be tested, and the reflected light generated in the light guide paths 26-30 is synthesized with the other branch light. A light detector 10 used as a light detecting means detects the intensity of the light synthesized by the photo- coupler 12. Multiple light guide paths 26-30 are connected to ports 15-19 respectively. Modulators 21-25 are installed, and the modulators 21-25 are driven at different frequencies. The frequency constituents corresponding to the driving frequencies in the interference constituents are detected. The reflection distribution is obtained based on the constituents. Level meters 31-35 are adjusted to measure the signal levels of various frequencies at the band width of 1Hz.
HORIGUCHI MASAHARU
YAMADA HIROAKI
