Low Intermodal Interference and Low Loss Hollow Core Fibers

A novel GTA-ST-HCF with optimized 4-fold gap-tube structure with a deflection angle achieves 0.040±0.003 dB/km loss and -63.6 to -73.2 dB/km IMI. Experiments also confirm the importance of IMI uniformity, imposing higher demands on HCF uniformity.