I have some theoretical understanding of photonics but what sucks is that with programming, you just fork shit and start hacking. With physics, just starting hacking is much harder.
For starters I would try to make a hologram. Once you can do that you can expand into photonics, it means that at least your basic understanding of setup and things like interference and stability are taken care of.
No, not at all, it's just that a proper optical setup is totally insulated from the surroundings so that a truck moving by 100 yards from your house doesn't wreck your carefully calibrated set-up.
Which usually translates into a lot of mass with as much vibration isolation as you can get.
And that in turn translates into large bins filled with sand (if you want to do this on the cheap).
And that in turn means you will most likely have to re-inforce your floor if you are in an ordinary building.
The best places to do work like this are in the middle of nowhere and away from any major roads. Even footsteps can be a problem for long running experiments where coherence is required.
It is a ton of fun though, and you will learn a lot.