Numerical Modeling of a Fused Deposition Modeled Embedded Polymer Fiber in a Micro-Dispensed Cladding for Optical Fiber Interconnects

Optical fiber interconnects transmit information between optical chips on PCB boards at higher bandwidths and with less energy requirements then traditional copper interconnects. Creating a smooth round fiber that connects components in three-dimensions is required for today’s fast data rates and tight packaging requirements. An additive manufacturing solution would need to satisfy these requirements to be a viable solution. However, fiber produced using fused deposition modeling (FDM) will sag under the force of gravity, non-homogeneous cooling, and surface tension when printed on a surface. Here we show by embedding a PMMA fiber produced using FDM printing, into a micro-dispensed optical urethane cladding, a smooth round fiber can be produced. We found in experimental studies that by controlling the processing conditions, we could produce round embedded fibers. Furthermore, we found in numerical simulation, that we could confirm those results at our processing conditions. Our results demonstrate that the roundness of a fiber can be measured at less than 1 micron when embedded within a cladding material and optical transmission rates of as high as 62%. We anticipate that embedding the fiber in the cladding material is one of the key steps in the larger laser enhanced-direct print additive manufacturing (LE-DPAM) process of producing smooth round plastic optical fibers. We anticipate that having the ability to produce a round fiber in the LE-DPAM process will be the foundation in the development of more sophisticated electro-optical computing devices.