Patent ID: 7519251

Claim:
An optical fiber acting as a slab-coupled waveguide and having a cross-section comprising: a two dimensional core ( 1 ) determining the horizontal confinement of the fiber's fundamental mode, a slab ( 2 ) extending substantially in a horizontal plane ( 2 ) and being, at least three times wider than the core, the core lying adjacent to the slab outside of it, the slab acting as a mode sink of the core, and a cladding ( 3 ) surrounding the core ( 1 ) and the slab ( 2 ), said cladding being made of one or several materials with refractive indices lower than the core and slab materials, said core, slab and cladding and any other protective or supportive structures attached to them forming an overall structure determining the mechanical properties of the fiber, wherein the cross-section of the fiber is formed to make the fiber significantly more flexible in the direction perpendicular to the plane of the slab than in the plane of the slab.