Alkali etched fiber Mach-Zehnder interferometer with compact sensor head

Area of Science:

• Photonics
• Optical Sensing
• Fiber Optics

Background:

• Fiber optic sensors are crucial for various detection applications.
• Traditional fiber Mach-Zehnder interferometers (MZI) can be complex and costly to fabricate.
• There is a need for simpler, more cost-effective MZI fabrication methods.

Purpose of the Study:

• To demonstrate a novel and simplified fabrication scheme for compact fiber Mach-Zehnder interferometers (MZI).
• To explore the potential of this MZI for micro-scale refractive index detection.

Main Methods:

• A Ge-doped fiber (GDF) section was sandwiched between two single-mode fibers.
• The GDF core was exposed via side polishing and etched using an alkali solution.
• A compact MZI was achieved by etching approximately half of the GDF core.

Main Results:

• A compact fiber MZI was successfully fabricated using the proposed method.
• The developed MZI exhibits a regular transmission spectrum.
• The fabrication process is characterized by low cost and environmental friendliness compared to traditional methods.

Conclusions:

• The demonstrated scheme offers an efficient and economical approach for MZI fabrication.
• The compact fiber MZI shows promise for micro-scale refractive index sensing applications.
• This method reduces sample consumption and enhances potential for sensitive detection.