Patent · US Expired

Optical time domain reflectometer using a tunable optical source

US5179420A · kind A · utility

43Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 7, 1991
Grant dateJan 12, 1993
Priority date
Expiry dateJun 7, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01M11/3127
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In an optical time domain reflectometer (OTDR), an optical signal is coupled to an optical fiber path to be tested, and back-scattered and reflected light from the optical fiber path is detected and used to determine loss-distance characteristics of the path. A control unit varies the wavelength of the optical signal by varying the temperature of a semiconductor laser constituting the optical source, so that the loss-distance characteristics for a plurality of different wavelengths are determined and can be displayed to show any wavelength dependent loss of the optical fiber path, which loss may be due to modal interference associated with closely spaced discontinuities in the path.

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