Suggest me a book about beam coupling through lenses

Not too sure if this is the right place to post.

Wanting to do some optics simulation on profile of beam after passing through a lens. Would be trying to use FDTD for it but I have little understanding on FDTD

Would like to ask for any examples that is similar for study or else anybody have some recommendation on books i can read on for it, for example on the topics for FDTD or optics simulation(using EM theory)?

Thanks for your help!

Quasioptical Systems: Gaussian Beam Quasioptical Propogation and Applications
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Hi
Does any body have this book.
Please Upload it if you have.
Thanks