Architecture for electromagnetic waveguide

An electromagnetic waveguide, such as an optical fibre, comprising:

• a hollow central core surrounded by a microstructured sheath formed by an assembly of elementary cells, the microstructured sheath comprising at least one elementary cell, called hybrid, comprising:
• at least one first cell inserted into at least one second cell;
• and
• at least one intermediate element connecting the at least one first cell with the at least one second cell;
• said at least one intermediate element having a cross section the area of which is less than or equal to 50% of the cross-sectional area of each of said cells that it connects;
• said at least one intermediate element having a refractive index less than or equal to the refractive index of each of said elementary cells that it connects;
• said at least one intermediate element having a tubular structure comprising a wall surrounding a central zone.