Phase sensitive parametric amplification of optical vortex beams

This work deals with the experimental parametric amplification of optical vortex beams (OVB) in a degenerate type I optical parametric amplifier (OPA). Results show that in a degenerate type I OPA, the amplification gain in the transverse plane depends on the pump beam profile as well as the relative phase between interacting beams. It leads to amplification or de-amplification that reshapes the signal beam in its transverse plane and preserves the orbital angular momentum when an optical vortex is carried by the signal beam. Then, new various patterns are obtained depending on phase matching condition, topological charge of the vortex and wave front of the pump beam.