Optical fiber sensor based on a radio frequency Mach-Zehnder interferometer

Area of Science:

• Photonics and Optical Sensing
• Interferometry
• Radio Frequency (RF) Technology

Background:

• Mach-Zehnder interferometers (MZIs) are widely used for sensing applications.
• Optical fiber sensors offer advantages in remote and harsh environment sensing.
• Radio frequency (RF) modulation provides a unique domain for signal processing and analysis.

Purpose of the Study:

• To propose and characterize an optical fiber radio frequency (RF) Mach-Zehnder interferometer (MZI) for sensing.
• To investigate the sensor's response to applied temperature changes.
• To analyze key performance parameters including sensitivity and operating frequency range.

Main Methods:

• An RF modulated laser source was injected into an optical fiber RF-MZI.
• The interference pattern was detected using a photodiode.
• Frequency sweeping with a network analyzer was employed to observe the interference in the RF domain.

Main Results:

• The proposed optical fiber RF-MZI sensor exhibited a linear response to applied temperature variations.
• The sensitivity, observation frequency range, and sensing arm length were discussed.
• The interference pattern was successfully observed in the RF domain.

Conclusions:

• The optical fiber RF-MZI is a viable and linear sensor for temperature sensing applications.
• The study provides insights into the design and performance of RF-based fiber optic interferometers.
• Further optimization of sensing arm length and operating frequency can enhance sensor performance.