Ultra-large mode field area single-mode all-solid anti-resonant fiber with open arc elements in the cladding

Area of Science:

• Photonics
• Optical Fiber Technology
• Materials Science

Background:

• Large mode area (LMA) fibers are crucial for high-power applications but often face challenges with maintaining single-mode performance and managing outer diameter.
• Existing LMA all-solid anti-resonant fibers (ARFs) typically use double layers of rods, limiting further increases in mode field area (MFA) and fiber size.
• Achieving both ultra-large MFA and high single-mode performance in a compact fiber design remains a key challenge in optical fiber development.

Purpose of the Study:

• To propose and theoretically investigate a novel ultra-large mode field area (MFA) single-mode all-solid anti-resonant fiber (ARF).
• To demonstrate the simultaneous achievement of ultra-large MFA and high single-mode performance through a unique cladding design.
• To present a fiber with a significantly reduced outer diameter (OD) compared to existing ultra-LMA fibers.

Main Methods:

• Utilizing open arc elements in the second cladding layer instead of traditional circular rods.
• Enlarging the core diameter and adjusting the inter-layer spacing of anti-resonant elements.
• Numerical simulations to analyze mode field area, single-mode performance (ratio of higher-order mode loss to fundamental mode loss), and outer diameter.

Main Results:

• An ultra-large MFA of 15647 µm² was achieved at 1.064 µm, double that of previously reported all-solid ARFs.
• A high single-mode performance was demonstrated, with the ratio of lowest loss of higher-order modes to fundamental mode loss reaching up to 23797.
• The designed fiber exhibits a remarkably small OD of 578 µm, significantly smaller than conventional LMA fibers.
• The proposed fiber shows wide parameter tolerance, indicating robustness in fabrication and application.

Conclusions:

• The novel all-solid ARF design with open arc elements offers a breakthrough in achieving ultra-large MFA and high single-mode performance simultaneously.
• The significantly reduced OD makes this fiber highly attractive for practical applications where space is a constraint.
• This innovative fiber design represents a promising candidate for the future advancement of ultra-large MFA fiber technology.