High resolution polarization-independent high-birefringence fiber loop mirror sensor

Area of Science:

• Optics and Photonics
• Fiber Optic Sensors
• Materials Science

Background:

• Traditional fiber loop mirrors (FLMs) are susceptible to external polarization perturbations, limiting their stability and application range.
• Existing FLM designs often require complex polarization controllers, increasing operational complexity and reducing system robustness.

Purpose of the Study:

• To theoretically and experimentally validate two novel all-polarization-maintaining (PM) high-birefringence (Hi-Bi) fiber loop mirrors (FLMs).
• To demonstrate the simplified construction and enhanced stability of these PM-Hi-Bi FLMs.
• To evaluate their performance as ultra-high resolution sensors.

Main Methods:

• Development of simplified FLMs using a PM-coupler and precisely rotated fused Hi-Bi fiber sections.
• Theoretical analysis of the optical behavior of the PM-Hi-Bi FLMs.
• Experimental validation of FLM performance and sensor resolution without averaging.

Main Results:

• Successful theoretical and experimental validation of two all-PM-Hi-Bi FLMs.
• Demonstration of immunity to external polarization perturbations due to fixed polarization states within the fiber loop.
• Achievement of ultra-high resolution sensing capabilities, with an experimental temperature resolution of 6.2 x 10^-4 °C.

Conclusions:

• The developed PM-Hi-Bi FLMs offer a simplified, stable, and robust alternative to classical FLMs.
• These devices are highly effective for applications requiring immunity to polarization fluctuations.
• The validated ultra-high resolution sensing capability opens new avenues for precise measurement in various fields.