Angular tolerances of non collinear optical parametric amplification in uniaxial and biaxial crystals

Optical parametric amplification (OPA) with multiple pumps is a promising technique for beam combining and amplification of an ultrabroadband femtosecond signal. In this context, the noncollinearity between the pumps and signal beams is required in order to transfer the phase incoherence between the different pumps to the corresponding idlers. Angular tolerances of phase matching in this configuration are critical parameters with regards to the efficiency and stability of the amplified signal, which requires judicious choices for the beams shaping. In this paper, the authors proposed an original approach enabling to calculate tolerances with respect to wavefront distortions, beam divergence and pointing instability. A general numerical code was developed and validated taking into account any noncollinear phase matching directions in or out of the principal planes of uniaxial and biaxial crystals.