Detecting optical fiber defects
US4021217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1975 |
| Grant date | May 3, 1977 |
| Priority date | — |
| Expiry date | Jul 8, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/88
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical fibers in long line communication links fail often in tensile strength. Analysis of tensile properties reveals a variation in tensile strength with fiber length, pointing to uncommon structural defects randomly occurring along the fiber length. Failures occur from crack propagation at these defects. The defects can be revealed according to the invention by nondestructive monitoring during production via off-plane light scattering. A narrow light beam incident across the fiber diameter is refracted in a pattern characteristic of the fiber geometry. Variations in that pattern are produced by structural variations in the fiber or by surface contamination. The nature of the pattern change can indicate the type of defect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.