Polymeric optical mixing rod coupler

Optical mixing rod couplers have been fabricated using extruded plastic tubing filled with optically transparent casting resins to form a waveguide-type mixing region. Asymmetric (1×19) splitter/combiners with plastic fiber and plastic-clad silica fiber pigtails have been made with efficiencies greater than 60% and power uniformities within 1-dB standard deviation. Tested as a combiner, the coupler had an average loss of -1.6 dB with a standard deviation of 0.71 dB. Tested as a splitter, it had an average loss of -14.9 dB with a standard deviation of 0.9 dB, and the excess loss was -2.0 dB. The results suggest that the coupler would be useful in a variety of short-distance optical interconnection applications where multimode step-index fiber is appropriate. It may also offer a higher yield than some competing, more complex techniques