Mode-resolved picosecond single-photon polarimetry maps modal dynamics in multimode fibers

Area of Science:

• Photonics
• Optical Fiber Communications
• Quantum Optics

Background:

• Polarization dynamics in multimode optical fibers (MMFs) are crucial for high-capacity communication and sensing.
• Current methods often fail to capture complete polarimetric information, overlooking orthogonal polarization states.
• Understanding these dynamics is essential for optimizing MMF performance.

Purpose of the Study:

• To develop a novel method for quasi-real-time observation of dual-polarization mode dynamics in MMFs.
• To introduce a single-photon polarimetric platform for comprehensive characterization of MMFs.
• To enable visualization and analysis of complex modal behaviors under stress.

Main Methods:

• Utilizing time-resolved single-photon avalanche diode (SPAD) arrays for simultaneous detection of orthogonal polarization channels.
• Implementing picosecond time-of-flight polarimetric readout.
• Developing a SPAD-based platform to reconstruct Stokes vectors across ~1000 spatial channels with 55 ps resolution.

Main Results:

• Demonstrated quasi-real-time observation of dual-polarization dynamics in few-mode fibers.
• Revealed spatio-temporal correlations between LP01 and LP11 modes under stress.
• Achieved mode-resolved Stokes retrieval with high sensitivity (minimum detectable modulation of 0.002) and signal-to-noise ratios up to 33 dB.

Conclusions:

• The developed SPAD-based platform enables ultrafast Stokes polarimetry in MMFs.
• This technology provides unprecedented insight into complex modal dynamics.
• Opens new avenues for advancements in classical and quantum photonics.