I'd say focus on the area you feel most comfortable on, that site is seriously great but a more modern version could bring to bear some useful things like numer

I'd say focus on the area you feel most comfortable on, that site is seriously great but a more modern version could bring to bear some useful things like numerical methods and interact with the trove of great research as well. https://optics.byu.edu/textbook https://optics.byu.edu/textbook is an open source wiki type textbox that I really enjoy.