Rayleigh-based OTDR with dynamic modal crosstalk suppression

Area of Science:

• Optical fiber communications
• Photonics
• Signal processing

Background:

• Few-mode fibers (FMFs) support multiple spatial modes, enabling higher bandwidth.
• Measuring modal crosstalk (XT) is crucial for FMF performance.
• Accurate splice loss measurement in FMFs remains challenging.

Purpose of the Study:

• To propose and demonstrate a novel approach for measuring modal attenuation of splice loss.
• To accurately measure splice loss variations of a purely LP11 mode group in FMFs.
• To suppress modal crosstalk (XT) during measurement.

Main Methods:

• Utilizing a Rayleigh-based Optical Time Domain Reflectometer (OTDR).
• Implementing a dynamic modal crosstalk (XT) suppression technique.
• Leveraging Brillouin loss interaction with a co-propagating Brillouin Stokes beam.

Main Results:

• The proposed approach effectively removes modal XT at the conversion point.
• Accumulated modal XT detected is significantly suppressed.
• Preliminary experiments demonstrated accurate measurement of splice loss variations for the LP11 mode group.

Conclusions:

• The novel Rayleigh-based OTDR with dynamic XT suppression is effective for FMF splice loss measurement.
• The technique accurately quantifies splice loss variations in the LP11 mode group.
• This method advances accurate characterization of FMFs.