We experimentally study the behavior of orbital angular momentum (OAM) of light in a noncollinear secondharmonic generation process. The experiment is performed by using a Type I BBO crystal under phase-matching conditions with femtosecond pumping fields at 830nm. Two specular off-axis vortex beams carrying fractional OAM at the fundamental frequency are used. We analyze the behavior of the OAM of the second-harmonic (SH) signal when the optical vortex of each input field at the FF is displaced from the beam's axis. We obtain different spatial configurations of the SH field, always carrying the same zero angular momentum.
展开▼
