[en] We give a direct method for obtaining exact solutions of the generalized nonlinear Schroedinger equation (iu_t + ε u_xx + 2 p | u | ² u + 2 iq (| u | ² u)_x = 0) describing the propagation of light pulses in optical fibers. From the general solutions in two particular cases (p = 0, q≠0, and p≠0, q = 0) we find various analytical solutions which are very important from the physical point of view. By using a suggestive phase diagrams description we classify all the obtained exact solution into one of the following categories: the one-soliton solutions, the 'algebraic' solitons, the bright and dark solitary waves and the regular periodic solutions. (Author)