Nondestructive method for attenuation measurements in optical hollow waveguides

A new method for characterizing hollow waveguides has been developed in which the laser radiation is coupled into the waveguide hollow bore through an optical fiber. By moving the distal end of the fiber along the waveguide we achieved scanning of the incident radiation in the waveguide at various points on the internal walls. This method can be employed for measuring attenuation without cutback or for detecting point defects on the waveguide's guiding layers.