Micro-fiber Mach-Zehnder interferometer based on ring-core fiber

Area of Science:

• Optical Engineering
• Fiber Optics
• Interferometry

Background:

• Mach-Zehnder interferometers (MZIs) are crucial optical devices.
• Conventional MZIs often face limitations in miniaturization and stability.
• Micro-fiber structures offer potential for compact and efficient interferometers.

Purpose of the Study:

• To demonstrate and investigate the performance of a novel micro-fiber Mach-Zehnder interferometer (MZI).
• To leverage the unique properties of ring-core fiber (RCF) for improved MZI performance.
• To achieve miniaturization, simplification, and enhanced stability in MZI devices.

Main Methods:

• Fabrication of the MZI by splicing a short ring-core fiber (RCF) segment with single-mode fiber (SMF-28).
• Utilizing a core-mismatch structure to separate and recombine light within the RCF.
• Investigating the optical path-length difference, extinction ratio, and mode suppression characteristics.

Main Results:

• The RCF-based MZI achieved a high extinction ratio of up to 18.2 dB.
• The device exhibited enhanced stability due to the RCF's higher numerical aperture and core structure.
• The core-mismatch design effectively separated light into the ring core (RC) and silica center (SC) modes.

Conclusions:

• The proposed RCF-based MZI offers a miniaturized and simplified design with superior performance.
• The higher numerical aperture of RCF enables greater optical path-length difference and higher extinction ratios.
• The unique RCF structure leads to lower sensitivity to external disturbances, enhancing device stability.