re: adaptive optics
The Minidisc works with a laser of 780 nm but other wavelengths are used with this principle in optical switches. One advantage of this idea is that magnetic switching like this would be far faster than deforming the mirror. Based on the current speed of these switches thousands of changes per second would be easy. Also the focal length could be lengthened perhaps so the deflection was more useful.
I'm trying to find the exact angle of deflection but they don't mention it in the original patents.