Optical time domain reflectometer using a tunable optical source
AssigneeBell Canada
InventorsVincent C.-Y. So, Michel Lessard
Life of this patent
Estimating the term…
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.
Claims13
An optical time domain reflectometer (OTDR) comprising:
- an optical source for producing an optical signal, and coupling means for coupling the optical signal to an optical fiber path, the optical source being tunable over a range of wavelengths in the region of a prescribed wavelength for said optical fiber path;
- means for detecting light from the optical fiber path;
- means responsive to the detected light for determining loss-distance characteristics of the optical fiber path;
- control means for controlling the optical source to vary the wavelength of the optical signal over said range;
- and
- display means responsive to the control means for displaying information representative of the determined loss-distance characteristics for a plurality of different wavelengths of the optical signal within said range.
A method of using an OTDR for determining characteristics of an optical fiber path, comprising the steps of:
- producing an optical signal using an optical source, the optical source being tunable over a range of wavelengths in the region of a prescribed wavelength for said optical fiber path;
- coupling the optical signal to the optical fiber path;
- detecting light from the optical fiber path;
- in response to the detected light, determining loss-distance characteristics of the optical fiber path;
- controlling the optical source using a control means to vary a wavelength of the optical signal over said range;
- and
- in response to the control means, displaying information representative of the determined loss-distance characteristics for a plurality of different wavelengths of the optical signal within said range.
An optical time domain reflectometer (OTDR) comprising:
- an optical source for producing an optical signal, the optical source being tunable to vary wavelength of the optical signal within a range of wavelengths differing by up to about 100 nm;
- coupling means for coupling the optical signal to an optical fiber path;
- means for detecting light from the optical fiber path;
- means responsive to the detected light for determining loss-distance characteristics of the optical fiber path;
- control means for controlling the optical source to vary a wavelength of the optical signal within said range;
- and
- display means responsive to the control means for displaying information representative of the determined loss-distance characteristics for a plurality of different wavelengths of the optical signal within said range.
Dependencies are inferred from the claim text.