I didn't see anything in my old calculus textbook. I'm in Modern Physics I (special relativity and early quantum theory), and the professors says we're going to use Fourier series/transform/integral in the next semester, Modern Physics II, which is really undergrad QM. I also might be taking a Modern Optics and Lab course in the fall, and someone mentioned the use of Fourier transform in the course. So, I would like to teach myself this. Thanks for any links.