Multimode fiber-optic Mach-Zehnder interferometer and its use in temperature measurement

Area of Science:

• Optics and Photonics
• Fiber Optic Sensing

Background:

• Traditional fiber-optic Mach-Zehnder interferometers often use single-mode fibers, limiting throughput.
• Multimode fiber interferometers offer increased throughput but suffer from speckle noise, hindering fringe shift detection.

Purpose of the Study:

• To develop a fiber-optic Mach-Zehnder interferometer utilizing multimode fibers with enhanced throughput.
• To address and overcome the challenge of speckle interference in multimode fiber interferometers for precise measurements.

Main Methods:

• Construction of a fiber-optic Mach-Zehnder interferometer employing multimode fibers.
• Implementation of a spatial filtering detector for fringe shift detection.
• Development of computer software to mitigate speckle disturbances.

Main Results:

• The developed interferometer demonstrated significantly greater throughput compared to single-mode fiber counterparts.
• Computer software effectively compensated for speckle noise, enabling reliable fringe shift detection.
• The system achieved a high temperature sensitivity of 72.3 ± 1.2 fringes/°C·m.

Conclusions:

• A multimode fiber-optic Mach-Zehnder interferometer with software-based speckle compensation is feasible and effective.
• This approach enhances throughput while maintaining high sensitivity for temperature sensing applications.