Modified J(1) ... J(4) method for linear readout of dynamic phase changes in a fiber-optic homodyne interferometer

Area of Science:

• Optoelectronics
• Fiber optic sensing
• Interferometry

Background:

• Fiber-optic interferometers are widely used for sensing applications.
• A J(1)...J(4) technique was developed for linear measurement of dynamic phase changes.
• This technique is independent of phase bias and random fluctuations.

Purpose of the Study:

• To address the limitations of the J(1)...J(4) technique.
• To enable measurement of the sign of Bessel function components.
• To improve the accuracy and applicability of fiber optic sensing.

Main Methods:

• A modified signal-processing technique is proposed.
• The method overcomes the inability to measure the sign of Bessel components.
• Implementation details focus on spectrum analyzer data processing.

Main Results:

• The modified technique allows for the determination of the sign of Bessel function components.
• This overcomes the magnitude-only limitation of the original J(1)...J(4) method.
• Enhanced linear measurement of dynamic phase changes in fiber interferometers is achieved.

Conclusions:

• The developed signal-processing technique significantly enhances fiber-optic interferometer capabilities.
• It resolves limitations in measuring dynamic phase changes.
• This advancement broadens the application scope of fiber optic sensing technologies.