Optical frequency domain polarimetry based on a self-referenced unbalanced Mach-Zehnder interferometer

Area of Science:

• Optical Engineering
• Fiber Optics
• Metrology

Background:

• Optical frequency domain polarimetry (OFDP) offers rapid, ultrawide dynamic range measurement of distributed polarization crosstalk.
• Interferometric phase noise limits the trade-off between measurement length and dynamic range in OFDP systems.
• Ambient noise further degrades signal quality in long-distance fiber optic measurements.

Purpose of the Study:

• To address the limitations of interferometric phase noise and ambient noise in OFDP.
• To develop a novel method for achieving long measurement distances with ultrawide dynamic range.
• To enable rapid and accurate evaluation of polarization crosstalk in long polarization-maintaining fibers.

Main Methods:

• Implementation of a self-referenced unbalanced Mach-Zehnder interferometer.
• Utilizing optical frequency domain polarimetry principles for distributed measurement.
• Experimental demonstration of the proposed method over a 9.8 km fiber link.

Main Results:

• Achieved an ultrawide dynamic range of 107.8 dB.
• Demonstrated successful measurement over a distance of 9.8 km.
• Recorded a short measurement time of 2 seconds with improved signal-to-noise ratio against ambient noise.

Conclusions:

• The self-referenced unbalanced Mach-Zehnder interferometer effectively mitigates interferometric phase noise.
• The developed OFDP method enables long-distance, high-dynamic-range polarization crosstalk measurements.
• This technique is suitable for evaluating polarization-maintaining fibers in dynamic environments.