Impact resistant light guide structure

A light guide structure comprising a first main surface and an opposite second main surface, configured to guide light in the light guide structure via total internal reflections at the first main surface and the second main surface, the light guide structure comprising an out-coupling arrangement configured to couple light propagating in the light guide structure out of it through at least one of the first main surface or the second main surface,

• wherein the light guide structure comprises two cladding layers and a core layer sandwiched between the cladding layers, the core layer comprising a core material and the cladding layers comprising cladding materials, respectively, the core material having its elasticity higher than elasticities of the cladding materials, and a refractive index for a design wavelength is substantially the same as refractive indices of the cladding materials for the design wavelength, the light guide structure comprising a plurality of alternating core layers and cladding layers.