Nested Anti-Resonant Hollow-Core Fiber for Low-Loss Multi-Mode Guidance

We present a multi-mode nested anti-resonant hollow-core fiber optimized for 1550 nm operation. This fiber achieves exceptional low-loss transmission and supports multi-mode guidance with propagation losses as low as 0.06 dB/m. Characterization reveals a wide bandwidth transmission window exceeding 250 nm, with loss <0.1 dB/m.