Laser-written polymer waveguides for embedded printed circuit board computing applications

Integrating polymer optical waveguides (WGs) for board-to-board high speed data communications require prototyping samples for proof-of-concept studies before moving to large scale production. A laser direct writing (LDW) method is shown as a cost savings alternative to photolithographic prototyping large substrate samples. The LDW setup consists of a 3-axis high-precision motion platform with a commercially available UV laser diode coupled to a lens-capped single mode fiber. The correlation between writing parameters and the resulting waveguide dimensions is discussed theoretically and confirmed experimentally with Dow Corning® OE-4140 UV-Cured Optical Elastomer Core and Dow Corning® OE-4141 UV-Cured Optical Elastomer Cladding for both multimode and single-mode feasibility. Laser written waveguide radial bends and crossings are also evaluated to show manufacturing capabilities for advanced prototyping designs. Polymer waveguides fabricated with the LDW method are experimentally validated with losses comparable to polymer waveguides manufactured with the photolithographic process ( \u3c 0.05 dB/cm). © 2014 SPIE