Robust gain bandwidth optimization in two-pump fiber optical parametric amplifiers with dispersion fluctuations

Gain bandwidth optimization in a two-pump fiber optical parametric amplifier (2P-OPA) with bounded zero-dispersion wavelength (ZDW) uncertainty is investigated. An analytical framework is devised for the design of maximum-bandwidth 2P-OPAs ensuring positive parametric gain, tunable gain spectrum quality, and robustness against ZDW fluctuations. By exploiting the polynomial nature of the phase mismatch, the design task is formulated as a non-convex optimization problem, which is then solved through convex programming techniques based on linear matrix inequality (LMI) relaxations. Compared to conventional nonlinear programming (NLP) algorithms such as genetic algorithm (GA), the proposed methodology exhibits superior computational efficiency, and guarantees convergence to globally optimal design parameters.