Plastic micro-optical modules for high-throughput interchip optical interconnections

Abstract

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. Furthermore, using ray-tracing software and radiometric simulation tools, we perform a sensitivity analysis for misalignment and fabrication errors on these plastic micro-optical modules and we study industrial fabrication and material issues related to the mass-replication of these components through injection-molding techniques. Finally we provide evidence that these components can be mass-fabricated in dedicated, highly-advanced optical plastics at low cost and with the required precision.

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

“…14]. In this paragraph however we bring forward the optical performances of' the FS( )1 component have been measured with a set-up as depicted in figure 5.…”

“…All our calculations were done on microlenses with a diameter of 200 tm (i.e. the maximum possible lens diameter with our fabrication technology if a pitch of 250 tm is desired [13,14]. We have performed RAD and EMP simulations of OPBs with microlenses of focal lengths ranging from 340 tm to 560 tm and for different working distances between the lenses and the emitter and detector array.…”

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

“…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.…”