Method for optical cable distance measurement by using optical cable tracker and optical cable tracker
AssigneesInno Instrument, Inc., Dh Infotech (Weihai) Inc.
InventorChuyuan Li
Life of this patent
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Abstract
The invention relates to a method using an optical cable tracker to measure optical cable distances and an optical cable tracker, which comprises a light source, an optical coupler, a phase modulator, a delay optical fiber, and an optical signal demodulation module. In the invention, optical cables are knocked to create disturbance. Not only can the optical cable be identified based on the corresponding interference produced by the light ray in optical cables, but also the distances from knock points to the local telecommunication terminals can be estimated. This facilitates the inspection, repair and maintenance of optical cables.
Claims10
A method of using an optical cable tracker for optical cable distance measurement, characterized in that the method comprises the following steps:
- (1) providing the optical cable tracker, which comprises a light source, at least two optical couplers, a phase modulator, a delay optical fiber, and an optical signal demodulation module;
- said light source, a first optical coupler, said phase modulator, and a second optical coupler are sequentially connected in series;
- said optical signal demodulation module is connected in parallel with said light source;
- said delay optical fiber is connected in parallel with said phase modulator;
- (2) Each time an optical cable distance is to be measured, first using said light source in said optical cable tracker to supply an incident light, which will be output and connect into at least one optical fiber of the optical cable to be measured, and beating at a test point of the optical cable to produce disturbance;
- (3) splitting, using the first optical coupler, the incident light into two beams, one of the two teams passes through said phase modulator and the other passes through said delay optical fiber;
- then merging said two beams using the second optical coupler;
- introducing the merged beams into said optical cable to be measured;
- after receiving the beating disturbance, a phase changes in the at least optical fiber;
- when the beams reach the other end of the optical cable and passes through a PC connector, a portion of the beams is reflected back;
- (4) splitting the reflected light, using the second optical coupler, into two light rays, one passes through said phase modulator and the other passes through said delay optical fiber;
- and then merging the two reflected light rays, using said first optical coupler, into an optical signal to be measured;
- (5) After said optical signal to be measured is demodulated, deriving disturbance information S1 and S2;
- (6) According to said disturbance information S1 and S2, calculating a distance from the test point to a local terminal of the optical cable.
An optical cable tracker for distance measurements of an optical cable, comprising:
- a light source, at least two optical couplers, a phase modulator, a delay optical fiber, and an optical signal demodulation module;
- wherein said light source, one of the at least two optical couplers, said phase modulator, and another of the at least two optical couplers are sequentially connected in series;
- the optical coupler at the end is directly connected with an optical cable to be measured;
- said optical signal demodulation module is connected in parallel with said light source;
- and said delay optical fiber is connected in parallel with said phase modulator.
Dependencies are inferred from the claim text.