Cubic-quartic optical soliton perturbation with lakshmanan-porsezian-daniel model by semi-inverse variational principle

We retrieve analytically a bright 1-soliton solution to a perturbed cubic−quartic Lakshmanan–Porsezian–Daniel model, using a semi-inverse variational principle. The perturbation terms are considered arising from the condition of maximum allowable intensity. The restrictions imposed by integrability considerations on the model parameters are enlisted. It is important that the other analytical approaches available fail to recover the analytical bright-soliton solution to the model with the maximum allowable intensity.