MULTI-FIBER LIGHT GUIDE, DEVICE WITH A MULTI-FIBER LIGHT GUIDE AND METHOD FOR PRODUCING THE SAME

A multi-fiber light guide (1) comprising- a multitude of light guiding fibers (3), each of the fibers (3) comprising- an elongated glass core (5), wherein- the cores (5) are surrounded by a glass cladding (7) so that- the cladding (7) with the cores (5) form a rigid continuous glass element (9), and- wherein the cores (5) have a higher refractive index than the cladding (7) so that light can be guided by total reflection along the glass cores (5), and wherein the glass element (9) of the multi-fiber light guide (1) has two abutting faces (10, 11), with the cores (5) ending in both abutting faces (10, 11), so that light can be guided along the cores (5) from one abutting face (10) to the other abutting face (11), and wherein- the glasses of the cores (5) and the cladding (7) contain alkali ions, and wherein- the alkali ions of the glasses are at least partly exchanged by alkali ions of a higher atomic number within an ion exchange layer (13) at each of the abutting faces (10, 11), the exchanged alkali ions within the ion exchange layer (13) imparting a compressive stress at the abutting faces (10, 11) .