Three-dimensional micro displacement sensor based on fiber SPR mechanisms.

Area of Science:

• Optoelectronics
• Nanotechnology
• Sensor Technology

Background:

• Traditional three-dimensional (3D) micro displacement sensing often involves complex systems combining multiple fiber micro displacement sensors.
• There is a need for integrated and simplified solutions for accurate 3D micro displacement measurement.

Purpose of the Study:

• To propose and demonstrate a novel 3D micro displacement sensor based on fiber surface plasmon resonance (SPR).
• To investigate the feasibility of a single-unit sensor for measuring micro displacements along X, Y, and Z axes.

Main Methods:

• Designed a sensor comprising a displacement fiber (cascaded eccentric dual-core fiber and graded multimode fiber) and a sensing fiber.
• Fabricated V-grooves and inclined SPR sensing areas on the sensing fiber.
• Utilized specific contact points between the displacement and sensing fibers to enable sensing of micro displacements in X, Y, and Z directions.

Main Results:

• The fiber SPR sensor successfully achieved 3D micro displacement sensing along the X, Y, and Z axes.
• Achieved wavelength sensitivities of 0.148 nm/µm (X), -3.724 nm/µm (Y), and 3.543 nm/µm (Z).
• Light intensity sensitivities were measured as -0.0014 a.u./µm (X), -0.0458 a.u./µm (Y), and -0.0494 a.u./µm (Z).
• Demonstrated that adjusting the eccentric dual-core fiber's core distance influences X-axis sensitivity and detection range.

Conclusions:

• The proposed fiber SPR sensor offers a self-contained solution for 3D micro displacement measurement.
• The sensor shows potential for applications in 3D micro displacement measurement and precision positioning.
• Further optimization of the eccentric dual-core fiber parameters can enhance sensor performance.