Interferometric fiber optic sensors

Area of Science:

• Photonics and Optical Engineering
• Sensor Technology
• Materials Science

Background:

• Fiber optic interferometers are crucial for sensing physical parameters like temperature, strain, pressure, and refractive index.
• Four primary types exist: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac interferometers.
• These sensors offer high sensitivity and remote sensing capabilities.

Purpose of the Study:

• To provide a comprehensive review of different fiber optic interferometer types.
• To discuss their operating principles, fabrication methods, and diverse application fields.
• To showcase recent advancements and practical potential in sensor technologies.

Main Methods:

• Review of existing literature on fiber optic interferometers.
• Categorization based on interferometric structure (Fabry-Perot, Mach-Zehnder, Michelson, Sagnac).
• Detailed examination of specific examples, including photonic crystal fiber and long period fiber grating (LPG) based sensors.

Main Results:

• Fabry-Perot interferometers, both extrinsic and intrinsic, are simple yet effective.
• Mach-Zehnder and Michelson sensors utilizing photonic crystal fibers demonstrate remarkable performance.
• Simultaneous multi-parameter sensing is achieved using LPGs in Mach-Zehnder and Sagnac configurations.

Conclusions:

• Fiber optic interferometers offer versatile and high-performance solutions for physical parameter sensing.
• Recent advancements, particularly with photonic crystal fibers and LPGs, expand their practical applications.
• Simultaneous multi-parameter sensing represents a significant development in this field.