Abstract: An improved fiber optic panel having a desired illumination pattern is assembled from at least two partial panels, each comprising a plurality of fully terminated parallel fibers. Two or more such partial arrays are combined to fabricate a optical fiber substrate having an arbitrary illumination pattern. The non-illuminated fiber lengths extending from the individual fiber terminations are removed before the two partial arrays are assembled, thus further enhancing the efficiency of the device. In a preferred embodiment the fibers of each partial array have a center-to-center spacing slightly greater than twice the fiber diameters, and the fibers of the two partial arrays are intermeshed to form a closely packed parallel array of fibers in which a fully terminated shorter fiber is located between two longer fibers.