An illumination system is provided that includes a spatial fiber arrangement with an optical element at the distal end of the fiber arrangement. The fiber arrangement has a first region including individual fibers with a significantly smaller active diameter in comparison with the individual fibers of a remaining region. The optical element at the distal end is assigned the remaining region. The fiber arrangement can be a rigid fiber rod that includes an intermediate region provided between the first region and the remaining region. The intermediate region suppresses stray light transfers between the first and remaining regions. The fiber arrangement can include an optical coupling element at a proximal end of the fiber rod.