Patent · US Expired

Test apparatus for optical waveguides

US4136960A · kind A · utility

2Cited by
1References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 4, 1977
Grant dateJan 30, 1979
Priority date
Expiry dateFeb 4, 1997

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/88
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

This specification describes a novel apparatus and method for testing optical wave guides to determine the optical attenuation and to locate faults in the optical fiber. The light for test purposes is launched into the fiber by one or more light beams that surround the wave guides and that are focussed to converge from around the circumference and at the axis of the wave guide; the convergence being at low angles of incidence, so that some of the light enters the wave guide. The remaining light launched into the wave guide in opposite directions at a location, nearer to one end than to the other, is measured at opposite ends of the wave guide. The ratio of the light at the opposite ends of the wave guide and the difference in the length of travel of the light from the region of entry to each end is used to compute attenuation. Faults are found by internal reflections of the light beam in the wave guide.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.