Method of characterizing a multimode optical fiber link and corresponding methods of fabricating multimode optical fiber links and of selecting multimode optical fibers from a batch of multimode optical fibers

The method of fabricating multimode optical fiber links comprising a light source and a multimode fiber, the method comprising:

• selecting a set of multimode optical fibers and a set of light sources;
• for each multimode optical fiber and for each light source in said sets, characterizing the multimode optical fiber link formed with said multimode optical fiber and said light source by (i) characterizing said multimode fiber using a measurement of the Dispersion Modal Delay (DMD) and delivering fiber characteristic data, (ii) characterizing said light source by at least three source characteristic curves obtained by exciting a nominal multimode fiber with said light source, scanning with a single mode fiber an output signal of said nominal multimode fiber, at different radial offset values r, from an axis of said nominal fiber where r=0 to a radial offset value r=a, where a is the core radius of said nominal fiber, and analyzing with a spectrum analyzer an output optical spectrum of said single mode fiber for each radial offset value r, wherein said source characteristic curves each show a source parameter as a function of said radial offset value r, and (iii) computing an Effective Bandwidth (EB) of said link, comprising calculating a transfer function using both said fiber characteristic data and each of said source characteristic curves;
• selecting only those multimode optical fiber links for which the effective bandwidth EB>3000 MHz-km.

The method of selecting multimode optical fibers from a batch of multimode optical fibers, the method comprising:

• selecting a batch of multimode optical fibers and a set of light source metrics;
• for each multimode optical fiber and each light source metric in said set, characterizing the multimode optical fiber link formed with said multimode optical fiber and said light source metric by (i) characterizing said multimode fiber using a measurement of the Dispersion Modal Delay (DMD) and delivering fiber characteristic data, (ii) characterizing said light source by at least three source characteristic curves obtained by exciting a nominal multimode fiber with said light source, scanning with a single mode fiber an output signal of said nominal multimode fiber, at different radial offset values r, from an axis of said nominal fiber where r=0 to a radial offset value r=a, where a is the core radius of said nominal fiber, and analyzing with a spectrum analyzer an output optical spectrum of said single mode fiber for each radial offset value r, wherein said source characteristic curves each show a source parameter as a function of said radial offset value r, and (iii) computing an Effective Bandwidth (EB) of said link, comprising calculating a transfer function using both said fiber characteristic data and each of said source characteristic curves;
• selecting only those multimode optical fibers for which the minimal calculated effective bandwidth over the whole set of light source metrics is >3000 MHz-km,
• wherein the set of light source metrics is obtained through measuring or modeling a representative set of light sources.