Optical backplane in planar technology

摘要

Optical interconnects are expected to overcome the limitations imposed by electrical interconnects. For board- to-board and board-to-multiboard communication we have developed an optical backplane for applications in mobile systems. Compared to existing realizations it is compact, rugged and has the potential to be fabricated at low cost. The main features of the optical backplane in planar technology are free space expanded beam transmission between boards and backplane and guided wave transmission within the backplane. No optical connectors are required. Due to the expanded beams and highly multimode waveguides large coupling tolerances of several 100 $mu@m are achieved. Low loss polymer backplane waveguides allow transmission length of more than 19 inches. Demonstrators for board-to-board interconnections and for ring and star networks have been realized. Transmission experiments at 1GBit/s have been successfully performed. First environmental test with respect to dust, moisture, temperature and vibrations showed the feasibility of the concept.