Ray Trace Analysis in Optical PCB Systems Using Micro-optic Connectors for 90° Deflection of Light Beams

Optical coupling efficiencies of distance and angular misalignment tolerances were investigated for a polymeric waveguide system and a silica fiber layer system through a ray trace simulation method. The polymeric waveguide system has 45deg-ended mirror connectors and a silica fiber layer system has 90deg-bent fiber connectors in an optical PCB. As misalignment tolerances have larger values, coupling efficiencies gradually decreased, which is more rapid at the second and third interfaces than the first interface of the optical transmission system. The lowest angular misalignment coupling efficiency within the test range is around 10 dB, which is larger loss than 5 dB in the case of distance misalignment. Optical 3 dB degradation distances of y-direction at the first interface are 320 mum and 390 mum for the polymeric waveguide system and fiber layer system respectively. Optical 3 dB degradation distances of other directions at three interfaces except for light propagation direction are within 50 mum.