Free-space micro-optical intra-MCM interconnection modules: performances, potentialities and limitations

We design and realize a scalable multi-channel free-space interconnection prototype with the potential for Tb/s.cm(2) aggregate bit rate capacity over inter- and intra- MCM interconnection distances. The component is prototyped in a high quality optical plastic, PMMA, using deep lithography with protons. At present data communication is achieved at 622 Mb/s per channel with a BER smaller than 10 (-13) for the 16 channels with inter-channel cross-talks as low as -22dB. We perform a sensitivity analysis for misalignments and study the impact of fabrication errors on the performance of the interconnection module in case injection moulding would be the preferred mass-fabrication technique. We provide evidence that these modules can be mass-fabricated with the required precision in optical plastics suited for heterogeneous integration with semiconductor materials

Photonic interconnects to silicon chips

A multi-channel free-space micro-optical module for dense MCM-level optical interconnections has been designed and fabricated. Extensive modeling proves that the module is scalable with a potential for multi-Tb/s.cm2 aggregate bit rate capacity while alignment and fabrication tolerances are compatible with present-day mass replication techniques. The micro-optical module is an assembly of refractive lenslet-arrays and a high-quality micro-prism. Both components are prototyped using deep lithography with protons and are monolithically integrated using vacuum casting replication technique. The resulting 16-channel high optical-grade plastic module shows optical transfer efficiencies of 46% and inter-channel cross talks as low as -22 dB, sufficient to establish workable multi-channel MCM-level interconnections. This micro-optical module was used in a feasibility demonstrator to establish intra-chip optical interconnections on a 0.6gm CMOS opto-electronic field programmable gate array. This opto-electronic chip combines fully functional digital logic, driver and receiver circuitry and flip-chipped VCSEL and detector arrays. With this test-vehicle multichannel on-chip data-communication has been achieved for the first time to our knowledge. The bit rate per channel was limited to 10Mb/s because of the limited speed of the chip tester

Free-Space Micro-Optical Interconnection Modules: The Missing Link for Photonics in Computing.

We report on the design, the fabrication, the characterization and the demonstration of scalable multi-channel free-space interconnection components with the potential for Tb/s.cm 2 aggregate bit rate capacity over inter-chip interconnection distances. The demonstrator components are fabricated in a high quality optical plastic, PMMA, using an ion-based rapid prototyping technology that we call deep proton lithography. With the presently achieved Gigabit/s data rates for each of the individual 16 channels with a BER smaller than 10 –13 and with inter-channel cross-talk lower than –22dB the module aims at optically interconnecting 2-D opto-electronic VCSEL and receiver arrays, flip-chip mounted on CMOS circuitry. Keywords: Micro-Opto-Mechanical-Systems, optical interconnects, VCSELs 1