Silicon photonics: the next fabless semiconductor industry

Something very surprising has been happening in photonics recently: the same foundries and processes that were developed to build transistors are being repurposed to build chips that can generate, detect, modulate, and otherwise manipulate light. This is pretty counterintuitive, since the electronics industry spends billions of dollars to develop tools, processes, and facilities that lend themselves to building the very best transistors without any thought about how to make these processes compatible with photonics (with the obvious exception of the processes designed to make CMOS and CCD camera chips).