The present disclosure relates to an optical fiber apparatus, including an optical fiber with at least two separate input guide sections provided at one end with a cross-section which is given at least in sections and comprises an edge section having a first radius, which converge and successively unite via a merging section to form a common main guide section with a cross-section which is given at least in sections and includes an edge section having a second radius, so that light introduced into an input guide section is guided into the common main guide section, where the merging section extends over a length which corresponds to 10-50 times the first radius.

A light-guide-part has width that gradually increases from first-end toward second-end and shape in which both sides of the light-guide-part in widthwise direction having optical axis interposed between are curved toward one-direction. An incidence-part has incidence-surface located in central part of the first-end of the light-guide-part and facing light source. The incidence-surface has shape in which both sides of the incidence-surface in the widthwise direction having the optical axis interposed between are curved toward the one-direction, curved in concave shape when the light-guide-part is seen from the one-direction, and curved in convex shape in cross section in thickness direction of the light-guide-part parallel to the optical axis. A reflecting-part has reflecting-surface inclined toward the one-direction on the second-end of the light-guide-part. The reflecting-surface has shape in which both sides of the reflecting-surface in the widthwise direction having the optical axis interposed between are curved toward the one-direction.

The present disclosure relates to an optical fiber apparatus, including an optical fiber with at least two separate input guide sections provided at one end with a cross-section which is given at least in sections and comprises an edge section having a first radius, which converge and successively unite via a merging section to form a common main guide section with a cross-section which is given at least in sections and includes an edge section having a second radius, so that light introduced into an input guide section is guided into the common main guide section, where the merging section extends over a length which corresponds to 10-50 times the first radius.

A lighting device comprising a first light unit having a light source and a first flat light guide having a linear light coupling surface and a light decoupling surface. A second light unit has a light source and a second flat light guide having a linear light coupling surface and a linear light decoupling surface. The first flat light guide and the second flat light guide are connected to each other in a single piece to form a light guide element. Opposite flat sides of the first light guide and opposite flat sides of the second light guide intersect in an intersection area. The first flat light guide has a deflection section between a first flat section and a second flat section of the first flat light guide. The first flat light guide and the second flat light guide form a U-shaped light guide element in a transverse plane.