Flexible gauge length intrinsic fiber-optic strain sensor using broadband interferometry [Invited].

Area of Science:

• Optical Engineering
• Metrology
• Materials Science

Background:

• Precise alignment monitoring is crucial in precision engineering for applications like machine tools and metrology frames.
• Existing strain monitoring methods may have limitations in adaptability and sensitivity.
• Fiber-optic sensors offer potential for robust and sensitive strain measurements.

Purpose of the Study:

• To present a novel fiber-optic strain measurement technique using broadband interferometry.
• To demonstrate a configurable system for varying gauge length and sensitivity.
• To address limitations in current fiber-optic sensing technologies for strain monitoring.

Main Methods:

• Utilized broadband interferometry with an unbalanced interrogation configuration.
• Overcame temporal coherence limitations by alleviating cavity length constraints.
• Investigated the impact of dispersion in intrinsic Fabry-Perot interferometers.
• Explored multisensor interrogation capabilities within a single optical system.

Main Results:

• Developed a fiber-optic strain measurement technique with configurable gauge length and sensitivity.
• Demonstrated that an unbalanced interferometer configuration removes cavity length limits.
• Showcased the necessity of considering fiber sensor dispersion for performance optimization.
• Reported successful multisensor interrogation using the proposed optical system.

Conclusions:

• The presented fiber-optic strain measurement technique offers a versatile solution for precision engineering.
• The broadband interferometry approach effectively enhances configurability and overcomes previous limitations.
• Consideration of dispersion is vital for optimizing intrinsic Fabry-Perot interferometer-based sensors.
• The system's multisensor capability enhances its applicability in complex monitoring scenarios.