According to http://motherboard.vice.com/read/within-10-years-computers-will-process-light-instead-of-electricity “Light Based Computers” will be here in the next 10 years.
We have been trying to keep it under wraps, but the Bad Voltage team already has one:
This is a lower-end model, a 486DX266 with 1MB RAM and a 100MB hard disk. Next to it you can see we also have a light-based hard disk.
Seriously though, what do you think about these light-based computers?
I’m not sure if their is a functional proof of concept even in existence.
“The challenge is to find a single material that can effectively use and control light to carry information around a computer,” noted Richard Curry, the current study’s lead investigator and a physicist the the University of Surrey, in a statement. “Much like how the web uses light to deliver information, we want to use light to both deliver and process computer data.”
They go on to describe a breakthrough, but it all seems very experimental at this point.
Seems like they are still having material science issues, which leads me to believe that 10 years is a reasonable lower bound, not an optimistic estimate for full production use. I could imagine you spending years just getting the supply chains together for such a new thing, testing, etc. Hardware is very hard. Especially tiny hardware with new materials.
Of course, the potential is massive. Here’s hoping they get it together sooner than later.
Hmmm,
Theoretically, If we used light for two things in the house with a central computer in the closet, It could be done really soon.
1st thing, is obvious, POWER, A small machine (tablet or at least the consumption of a tablet with solar cells tweaked for artificial light.
2nd thing, is to use the UV spectrum in all light bulbs in the house to use like wifi… The bandwidth is there.
Then all we have to do is have something “VNC client like (On the tablet/mini laptop that eats power like a tablet) thingy” to run remotely on the server in the closet. And Wala!!light based computing. (Sort of) 
I think it’s hard to say if this technology will replace current computers. But it’s important to do the research in this area. Maybe they find out it has advantages that can improve just some parts of Computers (e.g. very fast Memory). Also the results of this research could be helpful in cuantum computing.