Advancing Manufacturing Technology

iNEMI-IPSR Board-Level Optical Interconnect, Phase 2 (Expanded-Beam Module Interface)




Phase 2 Proposal Update:  IPSR Board-Level Optical Interconnect Application Interest Group (AIG), Terry Smith (3M) (July 12, 2018)

Project call for participation presentation (February 21, 2018)


This project is aligned with AIM (American Institute for Manufacturing Integrated Photonics), iNEMI, MIT MicroPhotonics Consortium, and industrial roadmaps.  These roadmaps predict that silicon-photonics-based transceiver modules will provide the most cost-effective solutions for on-board interconnections in the future.

This is based on the expected reduction of optoelectronic chip cost to be achieved via leveraging of the CMOS silicon foundry infrastructure. Before the anticipated cost benefits of silicon photonics can be realized, new high-performance and cost-effective solutions to optical packaging and connectorization must be developed. Optimum performance and functionality from silicon photonics devices requires single mode (SM) fiber/waveguide interconnect media.

Single mode operation requires precision (sub-micron) alignment in optical connections, both inside the package and in optical connectors; the tight mechanical tolerances needed in connector parts result in high cost components. To address the need for lower-cost SM connections, manufacturers have begun developing expanded-beam optical connectors.

The optical mode of the SM fiber (~ 10 microns diameter) is expanded to a larger collimated beam (e.g., 80 microns in diameter) thus relaxing the alignment tolerance between connector elements from submicron to a few microns...tolerances that can be held in injection molded parts. However, to date, expanded-beam versions of SM connectors have higher losses than desired by system designers, and thus have not yet been commercialized.

iNEMI-IPSR Board Level Optical Interconnect Project, Phase 1

Phase 1 addressed the assessment of the performance of prototypes of board-level interconnect systems based on single-mode (SM) fiber, expanded-beam optical coupling, and silicon photonics transceivers. This activity allowed evaluation of existing and developing components, and thereby identified gaps in the board-level technologies needed for practical implementation.  More information about Phase 1.

Proposed:  iNEMI-IPSR Board-Level Optical Interconnect Project, Phase 2 (Expanded-beam Module Interface Project)

Phase 2 of the AIM Photonics/iNEMI Board-Level Interconnect Demonstrator project will consist of specifying, designing, modeling, building and demonstrating a board-level optical interconnect system in which an expanded-beam optical connector interface will be developed for the chip module.

Given the complexity of the challenge, and the time and cost associated with fabrication of specialized tooling for optical coupling parts, the Phase 2 effort is subdivided into two sub-phases, 2a and 2b, each lasting approximately one year.

For Additional Information

David Godlewski
+1 717-651-0522