People have been doing "neat hacks" with nonlinear optics for a long time. None of it is remotely close to being usable as a photon-controlled photon gate. Al

People have been doing "neat hacks" with nonlinear optics for a long time. None of it is remotely close to being usable as a photon-controlled photon gate. All-optical switching (i.e. photonic computing) is like fusion power generation. It's been "right around the corner" for 20 years, yet we never seem to round the bend. It is, however, great for physicists writing grant applications. > look at this recent development: https://www.eurekalert.org/pub_releases/2020-11/ou-1ei110320 https://www.eurekalert.org/pub_releases/2020-11/ou-1ei110320... This was on HN here: https://news.ycombinator.com/item?id=24997573 https://news.ycombinator.com/item?id=24997573 My response here: https://news.ycombinator.com/item?id=25012670 https://news.ycombinator.com/item?id=25012670 Summary: this is converting information from the photonic domain to the thermal domain. Heat diffuses very slowly; you won't be able to put a lot of these devices near each other and run them at usable speeds without them causing each other thermal interference.