Hollow core optical fibre with yield tolerant microstructure

A hollow core optical fibre configured for guidance of an optical wave by antiresonance, comprising:

• a tubular glass jacket with a central lumen and a wall with a wall thickness;
• a hollow core defined in the central lumen and having in transverse cross-section a polygonal shape;
• and
• a cladding located in the central lumen and comprising flat planar glass membranes each having two opposite edges extending along a length of the hollow core optical fibre and a membrane thickness less than the wall thickness, the glass membranes arranged as a plurality of groups of glass membranes, each group comprising:
• a core boundary glass membrane defining one side of the polygonal shape of the hollow core;
• and
• at least one cladding glass membrane located between the core boundary glass membrane and the tubular glass jacket, all glass membranes in the group being spaced apart from one another;
• wherein every side of the polygonal shape of the hollow core is formed by a core boundary glass membrane, every glass membrane is anchored to the tubular glass jacket only along its two opposite edges, and there is no contact between any of the glass membranes.