Spend at least 30–60 minutes on a problem before looking at the manual. The mental effort of "getting stuck" is where the deepest learning happens.
If you are looking for specific problem types, the manual typically provides derivations for: Maxwell's Equations : Governing wave propagation in various media. Crystal Optics Solutions Manual Photonics Yariv
By respecting the rigor of Yariv and Yeh, and using existing solution sets as a guide rather than a crutch, you will move from simply passing a course to truly understanding the optical revolution. Spend at least 30–60 minutes on a problem