Detection of splices in an optical fiber
US4963020A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1989 |
| Grant date | Oct 16, 1990 |
| Priority date | — |
| Expiry date | May 5, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/3145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of detecting a splice in an optical fiber in the presence of noise generates a nulling filter from a segment of a signal received from the optical filter by determining a set of coefficients having an initial "1" followed by p-1 "0" values and w.sub.i finite impulse response filter values, where p is a prediction interval greater than the width of an expected splice signature. The received signal is processed by the nulling filter to remove exponentials from the received signal, leaving an error signal containing noise and splice information. The resulting error signal is processed by a correlation filter to reduce the noise in the error signal. The output from the correlation filter results in a noise reduced error signal with the splice appearing as a noticeable dip in the waveform. The waveform is passed through a threshold detector to identify the splice when the dip exceeds a predetermined threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.