Low-loss hollow-core fibers with improved single-modedness

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Hollow-core fibers (HCFs) offer potential for lower optical loss compared to traditional waveguides.
• A critical challenge in HCF development is the tradeoff between minimizing signal loss and ensuring single-mode operation.

Purpose of the Study:

• To demonstrate a novel strategy for achieving low loss and high single-modedness in HCFs.
• To introduce and experimentally validate the Perturbed Resonance for Improved Single Modedness (PRISM) technique.

Main Methods:

• Fabrication and characterization of a 19-lattice-cell HCF utilizing the PRISM design.
• Measurement of fundamental mode loss and higher-order mode loss to quantify single-modedness.
• Computational modeling to predict potential improvements in fiber performance.

Main Results:

• The PRISM HCF achieved a fundamental mode loss of 7.5 dB/km.
• Higher-order modes in the PRISM fiber experienced losses exceeding 3000 dB/km, demonstrating robust single-modedness.
• The achieved single-modedness surpasses previous HCF designs and rivals some solid-core fibers.

Conclusions:

• The PRISM technique effectively decouples core size from single-modedness, addressing a fundamental limitation in HCFs.
• This demonstration represents significant progress towards realizing the low-loss potential of hollow-core fiber technology.
• Further optimization of the PRISM design is expected to yield even lower measured losses.