Embedded micro-probe fiber optic interferometer with low nonlinearity against light intensity disturbance.

Area of Science:

• Optics and Photonics
• Metrology
• Fiber Optic Sensing

Background:

• High-precision displacement measurements are crucial for embedded systems.
• Light intensity fluctuations can significantly degrade the accuracy of fiber optic interferometers.
• Existing methods struggle to compensate for environmental disturbances like varying light intensity.

Purpose of the Study:

• To introduce a novel low-nonlinearity Michelson microprobe fiber interferometer.
• To analyze the impact of light intensity disturbance on measurement accuracy.
• To develop a robust method for high-precision embedded displacement detection.

Main Methods:

• Established an equivalent model for micro-probe sensing with a tilted target.
• Developed a Phase Generated Carrier (PGC) demodulation technique.
• Implemented a nonlinearity correction method to mitigate light intensity effects.

Main Results:

• The proposed method effectively avoids DC component variations caused by light intensity changes.
• Residual displacement errors were reduced from 4.36 nm to 0.46 nm.
• Sub-nanometer accuracy was achieved under low-frequency light intensity disturbance.

Conclusions:

• The novel Michelson microprobe fiber interferometer offers high-precision embedded displacement measurement capabilities.
• The PGC demodulation and nonlinearity correction method significantly enhances robustness against light intensity disturbances.
• This technology enables reliable sub-nanometer displacement detection in challenging environments.