High efficient optical parametric amplification of femtosecond pulses in MgO doped PPLN crystals at 3.4 µm.

We present a detailed numerical analysis of the optical parametric amplification (OPA) process in 5 % MgO doped PPLN photonic crystals, for the efficient generation of signal at 3.4 μ m. The current work calls attention to understand the dynamics of femtosecond pump laser for transferring cascaded energy from the pump to signal under the influence of the self-action effect which is a corollary of Kerr nonlinear response, cascaded χ (2) nonlinearities, and higher-order dispersion effects. Here, the dynamics of frequency shift of generated photon in a PPLN crystal is studied through OPA process by solving coupled nonlinear partial differential equation. It is observed that a small digression in the domain width from the coherence length profoundly increases the efficiency of the signal. The optimization condition for this frequency conversion process is discussed in detail using the pump pulse energy, domain size and input pulse width parameters along with the effects of cubic nonlinearity. [ABSTRACT FROM AUTHOR]