Patent ID: 11933605
Assignee: NEC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A computer implemented method for estimating core-cladding concentricity error (CCCE) in an optical fiber, the method comprising:
by the computer:
measuring at least one of a GAWBS spectra in the optical fiber selected from the group consisting of a GAWBS spectra parallel to a carrier, parallel GAWBS, and a GAWBS spectra orthogonal to the carrier (orthogonal GAWBS), a using a homodyne measurement technique in which a measurement laser is also a local oscillator;
subtracting half of the orthogonal GAWBS from the parallel GAWBS producing a subtracted GAWBS spectra;
identifying and removing any R0m modes from the subtracted GAWBS spectra producing a R0m removed GAWBS spectra;
iidentifying certain TR1m in the R0m removed GAWBS spectra and determining a total power under each TR1m mode in relation to a power under a highest R0m peak;
estimating the CCCE in the optical fiber by comparing R0m with TR1m; and
outputting an indicium of the estimated CCCE.