Optical interconnects on a flexible substrate by multi-material hybrid additive and subtractive manufacturing

Abstract

The integration of flexible photonic components into flexible electronics provides new opportunities for applications in imaging, sensing, and optical interconnection between devices. While most photonic devices are currently printed on rigid substrates, their integration on flexible polymer substrates has also been demonstrated in recent years. However, current technology of contact and non-contact processes limits the type and performance of optical devices on these flexible substrates and requires special processes or product design to get the entry and exit of optical interconnect end facets out of the substrate plane. Here, we show that by utilizing recent advances in additive manufacturing, we can print photonic interconnects directly on flexible substrates. For our proof-of-concept devices, our results demonstrate propagation losses of about 0.35 dB for the six cm samples, negligible changes in transmission losses through substrate bending at moderate bend radii down to about 5 mm, and no change in optical losses during fatigue testing up to 1000 cycles. These results demonstrate how flexible photonic devices can be produced using additive manufacturing techniques. A type of shape deposition manufacturing, laser enhanced-direct print additive manufacturing, is used to manufacture these devices. This system of micro-dispensing, fused filament fabrication, and laser subtraction has a unique ability to produce flexible optoelectronics in a single automated process. We anticipate flexible integrated optoelectronics devices based on this new technology to be a starting point in the development of more sophisticated devices.