Laser-direct writing of single mode and multi-mode polymer step index waveguide structures for optical backplanes and interconnection assemblies

摘要

A laser direct writing (LDW) method is implemented as a cost efficient polymer waveguide (WG) fabrication method for prototyping large substrates for optical backplanes and optical interconnection assemblies. The LDW setup utilizes a 3-axis air-bearing motion platform to reduce WG fabrication error to within +/- 0.15 mu m. A UV laser diode coupled single mode fiber with a focusing lens module is capable of LDW WGs at both multimode (50 mu m) and single mode (6 mu m) dimensions. Correlation between LDW parameters and fabricated WG dimensions using Dow Corning (R) OE-4140 UV-Cured Optical Elastomer (n(core) = 1.5142, n(clad) = 1.5064) is discussed theoretically and confirmed experimentally for both applications. A theoretical model is developed and utilized for producing LDW multi-mode (0.04 dB/cm, lambda = 850 nm) and single mode (0.55 dB/cm, lambda = 1310 nm) WGs. Measured propagation losses of LDW WGs are comparable to losses of photolithographic multi-mode (0.04 dB/cm, lambda = 850 nm) and single mode (0.59 dB/cm @ 1310 nm) WG builds. LDW multi-mode and single mode WG radial bend and crossing losses are evaluated for advanced optical communication channel routing capabilities and do not exhibit significant deviations from photolithographic-manufactured WG device loss. (C) 2014 Elsevier B.V. All rights reserved.