By solar energy application, that is more technical school than optics. So any high-tech universities would do just fine. Rochester Institute of Engineering, Virgina Tech, Stanford University, Cal-Tech...etc All these schools are excellent for your solar research.
However, for optics field nothing beats Stanford. Professor Dr. Hanrahan, who has been working very closely with my company in developing programs and techniques for computer generated graphics in relationship to light and optical device, i.e. camera lens. And he is just one of hundreds of professors in Stanford that their researches are used from private sector development to national space programs.
I suggest getting a book by
Barron's college review and read on other information. Or, visit their online portals.