High-sensitivity optical fiber temperature sensor based on a dual-loop optoelectronic oscillator with the Vernier...

Area of Science:

• Photonics and Optical Sensing
• Electronic Engineering
• Materials Science

Background:

• Traditional dual-loop optoelectronic oscillators (OEOs) typically use loops of significantly different lengths for noise reduction and mode selection.
• Optical fiber sensors are crucial for remote and harsh environment measurements.
• Achieving high sensitivity in optical fiber temperature sensors remains a key challenge.

Purpose of the Study:

• To propose and experimentally demonstrate a high-sensitivity optical fiber temperature sensor.
• To leverage the Vernier effect in a dual-loop optoelectronic oscillator (OEO) configuration for improved temperature sensing.
• To investigate the performance enhancement compared to single-loop OEO systems.

Main Methods:

• A novel dual-loop optoelectronic oscillator (OEO) architecture with two loops of slightly different lengths was designed.
• A section of optical fiber within one loop served as both the temperature sensing element and a delay component.
• The Vernier effect was utilized to enhance the frequency response of the OEO.
• Temperature sensing was performed by monitoring the frequency shift of the envelope peak in the OEO's frequency response.

Main Results:

• An obvious Vernier effect was successfully generated within the dual-loop OEO.
• The proposed sensor demonstrated a significant increase in sensitivity.
• Sensitivity improved from 6.625 KHz/°C in a single-loop OEO to 210.25 KHz/°C in the dual-loop configuration.

Conclusions:

• The dual-loop OEO incorporating the Vernier effect provides a highly sensitive optical fiber temperature sensing solution.
• This approach offers a substantial improvement in sensitivity over conventional single-loop OEO sensors.
• The proposed sensor is suitable for applications requiring precise temperature monitoring.