Kind of had experience with this.
I've designed stained glass panels - some used externally.
Basically, I would design the glass, pick the colours of the glass etc, and an artisan that our company uses would make up the design in stained glass.
Then a timber window manufacturer would build a window frame around the stained glass - framed between two sheets of glass. It's also possible to use the stained glass panel as the inner leaf of the double glazing. (Though it isn't great for insulation values of course).
I suspect it would be pretty difficult for someone without sufficient contacts in such trades, who one could rely upon to be of a particular quality, to do something like this though.