Direct readout of dynamic phase changes in a fiber-optic homodyne interferometer

Area of Science:

• Optics and Photonics
• Interferometry
• Phase Measurement

Background:

• Interferometers are crucial optical instruments for precise measurements.
• Measuring dynamic phase modulation is essential for various applications, including sensing and communication.
• Existing methods for dynamic phase measurement can be complex or limited in range.

Purpose of the Study:

• To develop and demonstrate a novel time-domain method for directly measuring the dynamic phase modulation index in interferometers.
• To establish a new technique for high-accuracy, wide-range phase deviation detection.

Main Methods:

• A novel time-domain analysis of interferometer output photocurrent was employed.
• The dynamic phase modulation index was directly calculated from the photocurrent waveform.
• Experimental validation was performed to assess the method's performance.

Main Results:

• The developed method successfully measured the dynamic phase modulation index directly from the photocurrent.
• A maximum dynamic phase deviation of 78 radians was experimentally achieved.
• A minimum detectable phase deviation of approximately 0.3 radians was demonstrated, indicating high sensitivity.

Conclusions:

• The novel time-domain method offers a direct and effective approach for measuring dynamic phase modulation in interferometers.
• This technique enables the detection of large phase deviations and possesses high sensitivity.
• The findings have potential implications for advanced optical sensing and metrology.