<title>Free-space micro-optical intra-MCM interconnection modules: performances, potentialities, and limitations</title>

Abstract

We design and realize a scalable multi-channel free-space interconnection prototype with the potential for Tb/s.cm2 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.

Free-space optical interconnection modules for 2D photonic-VLSI circuitry based on microlenses and GRINs

“…This way rays are emitted from the source in a quasi-random manner in accordance with their emission probabilities. An efficiency of 90% is reached for a working distance of 500 µm and a focal number for the lenses of 2.6 and the cross-talk for a neighboring channel is less than-40dB [21]. The optical performances of the FSOI component have been measured and the optical transfer efficiencies were found to be in the range of 40% to 46% with a cross-talk between neighboring channels lower than -22dB.…”

“…A second part integrates the counterpart mounting features and two micromirrors at a right angle to fold the 8 mm long light path over 180° (Figures 11a and 11b). We have already reported on the design, tolerance analysis [29,30], the rapid prototyping with deep proton lithography in Poly MethylMetAcrylate (PMMA) [21] of such an optical bridge for intra-chip interconnects [28,31], the opportunities for mass-replication through injection molding, and we have demonstrated its operation at 622Mbits/s [28] and at 2.48-Gb/s per channel [32]. This scalable 'optical bridge' concept allows for an increase in channel densities by using smaller lens diameters.…”

“…Nevertheless, when properly designed, they show superior interconnection densities to POF-based systems for intra-MCM interconnection distances [19][20]. In particular cases they even lend themselves to low-cost mass-fabrication through injection molding techniques [21]. This turns them into attractive and manufacturable complements to the guidedwave approaches and is our major driving force to study their design, fabrication and implementation in proof-of-principle demonstrator systems.…”

Assessment of vacuum casting replication technology for refractive and diffractive micro-optomechanical components

“…The optical pathway block [5,6] (Figure 15a) that we describe in this section of the paper is an optical interconnection module consisting of two components. The first one is a base plate featuring two arrays of spherical micro-lenses, which were discussed in the previous section, and a pair of alignment holes.…”

Plastic micro-optical modules for VCSEL-based free-space intra-chip interconnections: demonstrator testbeds with OE-FPGAs

“…The ray-trace model of the OIM, using the specifications of the VCSELs and detectors, the geometrical dimensions of the FPGA chip and the optical characteristics of the microlenses, yielded optical efficiencies of 83 % and cross-talk levels below -25 dB 12 . Also a tolerancing study was carried out to predict the effect of fabrication and alignment errors of the OIM.…”