This work formulates, theorizes, and presents a novel method of modelocking ultrafast sources with short gain media. By appropriately balancing the complex interplay of elements within the laser cavity, a passive self-similar pulse solution can be obtained which can support one to two orders of magnitude more energy than other pulse evolutions in an analogous system before encountering wave-breaking. A purely analytical model which describes this pulse evolution is presented, and the results are shown to match simulation and explain the connection between this evolution in the solid state, and the analogue evolution in fiber laser systems. Several methods for realizing this pulse evolution experimentally are detailed and shown to be feasible through numerical simulation. Additionally, theoretical and numerical work is presented which describe a self similar evolution in passive fiber with increasing nonlinearity. Lastly, numerical experiments are presented which detail the feasibility of a nonlinear-dispersive self similar evolution in a fiber laser.