A fiber optical illumination delivery system, which is effective in reducing
the
effects of source coherence. The system preferably utilizes either a single bundle
of optical fibers, or serial bundles of optical fibers. In the single bundle embodiment,
the differences in optical lengths between different fibers of the bundle is preferably
made to be equal to even less than the coherence length of the source illumination.
In the serial bundle embodiment, the fibers in the other bundle are arranged as
groups of fibers of the same length, and it is the difference in lengths of these
groups which is made equal to, or even more preferably, less than the overall difference
in length between the shortest and the longest fibers in the other bundle. Both
of these fiber systems enable construction of illumination systems delivering a
higher level of illumination, but without greatly affecting the coherence breaking
abilities of the system, thus enabling a generally more applicable system to be constructed.
