Device for evaluating the light-transmitting characteristics of optical fibers

摘要

To intercept and measure radiant energy back-scattered from the entrance end of an optical fiber irradiated by a pulsed laser beam, a semitransparent mirror is interposed between the irradiated fiber and a first lens assembly focusing the laser beam upon its entrance end while a second lens assembly directs reflected light rays toward a photodetector feeding an electronic processor. An extremity of the fiber including its entrance end is received in a chamber with light-absorbing walls filled with a liquid of substantially the same refractive index as the fiber; the mirror may be disposed either in front of the chamber entrance or in its interior.