If I remember correctly, quantum computers went from theory to prototype in a decade. What are the barriers to modelling a core that uses these in software and then effectively printing them, and adding a conventional computer interface at the edge?
If it's economically viable, I'd bet we will see it in 15 years. There are libraries for quantum algorithms in multuple languages, and I remember trying to learn them in Haskell pre-2010, with the assumption that by the time I wrapped my head around it a decade or two later, there would be computers to run it on. I gave up on that, but from an investor perspective, a game changing improvement in classical compute tech is worth considering exposure to.
Are you seriously confident this optical compute model, if economical, is 30+ years away?