Interferometric fiber-optic bending/nano-displacement sensor using plastic dual-core fiber

Area of Science:

• Optoelectronics
• Fiber optics
• Nanotechnology

Background:

• Interferometric sensors offer high sensitivity for measuring physical parameters.
• Fiber-optic sensors are advantageous due to their small size, immunity to electromagnetic interference, and remote sensing capabilities.
• Plastic optical fibers provide flexibility and cost-effectiveness compared to silica fibers.

Purpose of the Study:

• To demonstrate a new interferometric fiber-optic sensor for detecting bending curvature and nano-displacement.
• To utilize a plastic dual-core fiber for enhanced sensor performance and applicability.
• To investigate the resolution limits of the developed sensor system.

Main Methods:

• An interferometric sensor was designed using a plastic dual-core fiber.
• Light was coupled into both cores, guided, and reflected by a mirror at the fiber end.
• Interference patterns from reflected light were analyzed to detect fiber bending.
• A slit and photodetector system was employed for interrogating interference shifts.
• The sensor's resolution for bending curvature and nano-displacement was experimentally determined.

Main Results:

• The sensor successfully detected bending-induced interference shifts.
• A resolution of approximately 3x10⁻⁴ m⁻¹ was achieved for bending curvature sensing.
• A resolution of approximately 70 nm was achieved for nano-displacement sensing.
• The plastic dual-core fiber enabled effective interferometric operation.

Conclusions:

• The developed interferometric fiber-optic sensor based on plastic dual-core fiber is effective for measuring bending curvature and nano-displacement.
• The sensor demonstrates high resolution, making it suitable for various sensing applications.
• This technology offers a promising approach for miniaturized and sensitive optical measurement systems.