Remote Michelson interferometric phase sensor based on dual-core fiber transmission and linear phase demodulation

Area of Science:

• Optics and Photonics
• Fiber Optic Sensing
• Interferometry

Background:

• Remote phase sensing is crucial for various physical quantity measurements.
• Environmental disturbances and phase noise limit the performance of traditional sensors.
• Existing methods often suffer from limited linear demodulation range.

Purpose of the Study:

• To propose and demonstrate a remote Michelson interferometric phase sensor.
• To achieve efficient suppression of environmental disturbances and phase noise.
• To extend the linear phase demodulation range for remote sensing.

Main Methods:

• Utilizing dual-core fiber for synchronous transmission of sensing and reference lights.
• Implementing two optical phase-locked loops for linear phase demodulation.
• Employing a fiber stretcher to eliminate residual phase noises and a phase modulator to track phase changes.

Main Results:

• Successfully realized remote phase sensing over a 20 km fiber link.
• Achieved less than 3% nonlinear phase error over a 3π range.
• Extended the linear phase demodulation range by more than 10 times.

Conclusions:

• The proposed dual-core fiber-based Michelson interferometric sensor offers robust and highly linearized remote phase sensing.
• The system effectively suppresses environmental disturbances and phase noise.
• Demonstrates significant potential for measuring diverse physical quantities remotely.