公开(公告)号：JPH10267859A

公开(公告)日：1998-10-09

申请号：JP5717798

申请日：1998-03-09

Applicant: LUCENT TECHNOLOGIES INC

Inventor： JAKOBSEN CHRISTIAN ,  PEDERSEN FLEMMING ,  PENN LEONARDO M ,  BREWER TRACY E ,  KARP AARNE ,  SMITHGALL DAVID H

IPC: G01M11/00 ,  G01N21/88 ,  G01N21/958

Abstract: PROBLEM TO BE SOLVED: To detect air bubbles, lamination of a layer, etc., by detecting a light coupled to a coat layer when the light coupled to the coat layer along an optical fiber is reflected outward from the optical fiber because of a defect present in the coat layer. SOLUTION: A monochromic coherent light beam 12 is projected to a secondary coat layer 13 of an optical fiber with an angle of 5-30 deg.. A coupling point 17 where the light beam 12 is coupled to the second coat layer 13 of the optical fiber is separated by a predetermined distance from a photodetector 15. Air bubbles included in a primary coat layer 11 and the secondary coat layer 13 and a lamination between the primary coat layer 11 and the optical fiber reflect the light to the photodetector 15. A microprocessor receiving an output from the photodetector 15 processes the output, thereby determining whether the air bubbles or the lamination is present, with transmitting information to a production process.