This is odd, but...
A solar sail is driven by the pressure of photons making contact with the sail, right? The reflection generates a pressure. The problem with a solar sail, though, is that one can only go away from Sol (or whatever other star you might happen to be traveling near.)
So I was thinking, what if a spacecraft were built with extremely massive solar arrays with really high efficiency, like exceeding 50% (I know our best technology only gets us to about 20% right now, but bear with me.) The power generated by these solar panels is then routed to a really, really powerful laser which can be pointed in any direction. If the laser is strong enough, will the photons streaming from it act as a rocket exhaust to give the spacecraft a thrust comparable to a solar sail? If this works, and the solar panels exceed 50% efficiency, I think it could be used to fly towards Sol, thought quite slowly since the solar panels would reflect some photons.
Or do I just misunderstand solar sails?