Recently I started thinking about an analog optical device capable of matrix multiplication. After some online research, the Mach-Zehnder interferometer seems to have been adapted by a German company into a full addon optical based matrix multiplication system.

It is a very interesting concept and the company Q.Ant has delivered working products and software. Apparently it can greatly speed up certain training applications and future designs will solve some of the current problems.

The energy and performance advantages seem to be worth the R&D. If some form of optical memory to replace DRAM in the chain could be designed, that would solve several conversion costs between optical to digital.

Either way it is pretty cool to do math this way, basically just using light.