Link to my free E-book on the Nonlinear Schrodinger Equation:
https://github.com/OleKrarup123/NLSE-primer/blob/main/NLSE_primer.pdf
Explanations of OTDR:
https://www.rp-photonics.com/optical_time_domain_reflectometers.html
https://www.fiberoptics4sale.com/blogs/archive-posts/95045446-how-to-test-a-fiber-optic-system-with-an-otdr-optical-time-domain-reflectomer?_pos=3&_sid=83cbcb7ab&_ss=r
