The invention relates to an anti-resonant
hollow core fiber (1000), comprising a
fiber cladding (2000) which has an inner bore (2200), a
fiber longitudinal axis (2300) and a fiber core
radius R_
Fiber (2310), a number of anti-
resonance units (3000), each comprising • an ARE element (3100), • an NE element (3400), • a DNE element (3900), wherein the anti-
resonance units (3000) are spaced apart from one another and arranged contact-free at desired positions on an inner side (2150) of the inner bore (2200), wherein in the anti-
resonance units (3000) • the ARE element (3100) has a circular cross-section, • the NE element (3400) is arranged in a first
interior space (3170) of the ARE element (3100), and • the DNE element (3900) is arranged at least partially in a second
interior space (3470) of the NE element (3400). According to the invention,that in at least one anti-resonance unit (3000) • the NE element (3400) has a circular arc-like cross-section and is connected to the DNE element (3400) along two connecting seams (3700, 3700'), • the DNE element (3900) has an oval cross-section, and • in the cross-section, a sum of the distances of any point on a DNE element wall (3950) from two focal points (4000, 4000') is equal for all points to less than 15% of the sum of the distances.