I think some people don’t get that a nonlinear interferometer IS a switching element, its use is AS a logic element. In the late 70’s, Toni Bischofberger and YR

I think some people don’t get that a nonlinear interferometer IS a switching element, its use is AS a logic element. In the late 70’s, Toni Bischofberger and YR Shen put a liquid crystal inside an interferometer and observed switching effects using a single shot ruby laser. The theory had previously been worked out, and there were initial experiments at Bell Labs. Shen et al used liquid crystal because they could vary the nonlinearity greatly by temperature: they were exploring that entire parametric space. Cut to 2020. So they reduced the size to the 100 micron level, so what? Electron gates are at the 10nm level in production, and experimentally, at the few atoms level. While sub diffraction optical effects have been reported, one end of the wire is still a few microns in size. So perhaps someone can find an application for these Si gates, but not in switching logic.