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.

公开(公告)号：JPH11271175A

公开(公告)日：1999-10-05

申请号：JP2115399

申请日：1999-01-29

Applicant: LUCENT TECHNOLOGIES INC

Inventor： JAKOBSEN CHRISTIAN ,  PEDERSEN FLEMMING

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

Abstract: PROBLEM TO BE SOLVED: To judge whether a defect such as air bubbles exists in an optical fiber by discharging light in a direction that is vertical to the axial direction of the fiber to the covering of the optical fiber and detecting the presence or absence of third reflection rays from the device of the covering in addition to the first and second reflection rays at the boundary between air and the covering. SOLUTION: Optical beams 12 are applied to a covering 14 for surrounding an optical fiber 3 in a direction that is vertical to the axial direction of the fiber 3. Due to the difference in the refractive index between air and the covering 14, first rays 15 and second rays 17 are reflected at a boundary 16 between air and the covering and at a boundary 18, respectively. When no defect exists in the fiber 3, only the first and second rays 15 and 17 are detected by a linear photosensor array 9. However, when a defect 35 exists in the fiber 3, third rays 36 are reflected due to the defect 35 and are focused on the array 9. In this case, all three rays 15, 17, and 36 are detected for the array 9, thus judging the presence of the defect. In this manner, by utilizing the optical characteristics of the fiber covering 14, a defect can be detected.