One- and two-dimensional single-mode differential fiber-optic displacement sensor for submillimeter measurements

Area of Science:

• Optoelectronics
• Fiber Optics
• Metrology

Background:

• Differential fiber-optic sensors offer precise displacement measurement capabilities.
• Submillimeter measurement accuracy is crucial in various scientific and industrial applications.
• Existing sensor technologies may have limitations in linearity or multi-axis independence.

Purpose of the Study:

• To demonstrate the working principle of one- and two-dimensional differential fiber-optic displacement sensors.
• To analyze sensor linearity, travel range, and sensitivity.
• To propose a design chart for optimizing sensor performance.

Main Methods:

• Utilizing the overlap integral method and Gaussian approximation for fiber-optic fields.
• Developing one-dimensional (1D) and two-dimensional (2D) sensor configurations with specific fiber arrangements.
• Experimentally simulating sensor responses using a high-precision robotic system.

Main Results:

• Demonstrated intrinsically linear sensor responses over a wide travel range.
• Confirmed independent measurement of each axis for the 2D sensor.
• Characterized linearity, travel, and sensitivity based on fiber gap distance.

Conclusions:

• The developed differential fiber-optic displacement sensors are suitable for submillimeter measurements.
• The proposed design chart aids in optimizing sensor performance by considering nonlinearity, travel, sensitivity, and gap distance.
• The independent axis measurement capability of the 2D sensor enhances its utility in complex applications.