Optimum conditions for soliton launching from chirped sech² pulses

Simple and exact analytical formulas are derived for the optimum power and width of chirped sech² pulses that maximize the energy transfer to the fundamental soliton. The maximum achievable energy transfer is shown to be equal to (formula presented), normalized relative to the initial pulse energy, where a is the laser phase-amplitude coupling factor. The critical values of the a factor for the fundamental soliton are given simply in terms of the normalized pulse amplitude A by α_cr = (4A² -1)^½.