Pulse propagation Equation - Optics

We all have heard of pulse propagation equation or let's say Shrodinger's Non linear Pulse propagation .This is the most important equation in optics which governs the propagation of a wave inside fibers and all the DWDM systems are designed keeping this equation in mind and improvements are done keeping this equation in consideration . So let's go to the mother of all equations as far as optics is concerned .Please refer the image which denotes the NLSE

E---Electromagnetic field can be considered and distance travelled

Alpha-Indicates fiber los coefficient

Beta2-- Indicates group dispersion velocity or group delay

Beta3 ---Dispersion slope

Gamma--Indicates non linear coefficient t related to kerr effect

The above equation also indicates why chromatic dispersion is helpful in mitigating Kerr Non linearities across G.652 and also why we design our systems to compensate Linear and NLI in order for the wave to propagate along the fiber .