The gap between memory and xPU bandwidth has been constant at 2-3X over the last two decades and, by now, there is a 1,000X gap between what is possible and what is required by applications such as AI. N5/N3, and Wafer Scale Integration (WSI) represent the extreme attempt to keep classical Moore’s Law afloat but, like fossil energy this attempt is not sustainable; there is not much room for improvement beyond 12” wafers and 3-nanometer CMOS. We are approaching an inflection point: an innovation tsunami is looming. Silicon photonics may leverage the existing semiconductor technology and its supply chain, to provide the foundation for Optical Computing, which is faster than Electronic Computing, more power savvy, but whose roadmap does not rely on nanometer manufacturing and does not suffer of its complexity. Most optical computing research aims at replacing electronic components with optical equivalents, building an optical digital computer processing binary data. While this approach appears to offer the best short-term commercial prospects for optical computing, since optical components could be integrated into traditional computers to produce an opto-electronic hybrid, these devices use 30% of their energy converting electronic energy into photons and back. More unconventional research aims at building all-optical computers that eliminate the need for optical-electrical-optical (OEO) conversions.