Double-looped Mach-Zehnder interferometer for achieving multiple ring-down interferograms.

Area of Science:

• Optics and Photonics
• Interferometry
• Fiber Optics Sensing

Background:

• Fiber-loop ring-down (FLRD) systems are used for loss measurements.
• Conventional FLRD systems require extensive scanning for data acquisition.
• Accurate loss characterization is crucial for optical systems.

Purpose of the Study:

• To develop a novel double-looped Mach-Zehnder interferometer.
• To acquire continuous ring-down interferograms efficiently.
• To accurately measure intrinsic losses of fiber-loop cavities.

Main Methods:

• Utilizing two fiber-loop cavities with slightly different optical path lengths.
• Employing Vernier-like pulse train generation and interference.
• Scanning a delay line over a short range (millimeters) to obtain multiple interferograms.

Main Results:

• The proposed system successfully acquired continuous ring-down interferograms.
• Intrinsic losses of the fiber loops were estimated.
• The measured combined loss showed a minimal difference of 0.06 dB compared to a conventional system.

Conclusions:

• The double-looped Mach-Zehnder interferometer is an effective tool for continuous ring-down interferogram acquisition.
• The system offers high accuracy in loss estimation with reduced scanning requirements.
• This method provides a precise and efficient alternative for characterizing optical fiber losses.