Packaging and Assembly for Integrated Photonics—A Review of the ePIXpack Photonics Packaging Platform

Abstract

Abstract-We review recent work done by the photonics packaging platform ePIXpack that serves the academic community with packaging & assembly developments in the area of integrated photonics. The paper includes recent examples of our packaging and assembly work, covering a broad range of technologies from silicon photonics to InP based devices. Index Terms-Hybrid integrated circuit packaging, Photonic integration, Silicon-on-insulator (SOI) I. INTRODUCTIONThe need for next generation carrier networks with capacities of 100Gbit/s transmission rate and beyond is driven by ubiquitous internet access, video driven IP traffic, highdefinition TV broadcast etc. [1,2]. Networks will need to handle constantly increasing bandwidth, while the underlying fiber infrastructure naturally only undergoes slow changes. This requires advanced solutions for high transmission capacity, which eventually can only be provided by integrated photonics devices. One option is silicon photonics. Siliconon-Insulator (SOI) is becoming an attractive passive optical integration platform due to its flexibility in terms of optical design. Thin SOI (~200nm) yields high-index contrast nanowaveguides [3] However, there still remain many challenges for silicon photonics to become an accepted technology in optical communications, e.g. integration of the source, efficient modulation, and polarization dependence.

MEMS tunable silicon photonic grating coupler for post-assembly optimization of fiber-to-chip coupling

“…Our device combines the low power consumption of MEMS tuning with a tuning range of 6 µm along the critical coupling dimension. These results show that our device is able to compensate for the typical drift caused by glued fiber connections or assembly misalignment of up to 3 µm [8] by using standard 5 V CMOS voltage levels. Our results suggest that the presented technology has the potential to overcome current roadblocks to silicon photonics proliferation.…”

“…However, errors in fiber-tograting alignment incurred during assembly and through long-term drift of glued parts result in significant and variable optical losses, hampering the spread of this technology (Fig. 1b) [8].…”

New dynamic silicon photonic components enabled by MEMS technology

“…Moreover, using MEMS, we can reconfigure the waveguide geometry to demonstrate dynamic dispersion tuning of 800 ps/nm/km in a silicon photonic ring resonator waveguide with a low, anomalous dispersion, with applications in nonlinear optics. Finally, we have experimentally demonstrated the first MEMS tunable grating coupler for post-assembly optimization of fiber-to-chip light coupling, able to compensate for the typical drift caused by glued fiber connections or assembly misalignment of up to 3 µm in one direction, 21 by using standard 5 V CMOS voltage levels. Our results show the potential of silicon photonic MEMS technology for enabling densely integrated reconfigurable silicon photonic systems.…”

Grating-Assisted Fiber to Chip Coupling for SOI Photonic Circuits

“…Grating couplers have much a better alignment tolerance amounting to ±2.5 µm 1 dB power penalty and a CMOS compatible planar processing that is suitable for high volume manufacturing and wafer-scale testing. Commercial packaging service ePIXpack offers multiport fiber array connector of up to 32 ports [63][64][65]. The fibers are mounted vertically on a v-groove bottom with a glass lid that is polished at near normal coupling angle to the SOI chip, along with a glob-top encapsulation (see Figure 18a).…”