Embedded multicore hollow fiber with high birefringence

Area of Science:

• Optical Fiber Technology
• Materials Science
• Photonics

Background:

• Birefringence in optical fibers is crucial for polarization control.
• Existing methods for controlling birefringence can be complex or limited.
• Hollow-core fibers offer unique light-guiding properties.

Purpose of the Study:

• To fabricate and demonstrate a multi-core hollow fiber (MCHF) with controllable birefringence.
• To investigate the relationship between fabrication parameters and MCHF birefringence.
• To explore potential applications of MCHF in optical sensing and interferometry.

Main Methods:

• Fabrication of MCHF using a modified suspended core-in-tube preform technique.
• Control of core ovality via applied pressure and drawing temperature during preform processing.
• Integration of MCHF with a single-mode fiber using fuse-tapering to create an in-fiber Mach-Zehnder interferometer.

Main Results:

• Successful fabrication and demonstration of MCHF with tunable birefringence.
• Demonstrated an in-fiber Mach-Zehnder interferometer using MCHF with 90.38% visibility.
• Achieved splice loss of less than 2 dB between the MCHF and single-mode fiber.

Conclusions:

• The proposed MCHF offers a promising platform for advanced optical devices.
• Tunable birefringence in MCHF can be achieved by controlling core ovality.
• MCHF shows potential for polarization-insensitive in-fiber interferometers and biosensing applications.