Dynamics of a paired optical vortex generated by second-harmonic generation

作者：Toda Y^*; Honda S; Morita R

来源：Optics Express, 2010, 18(17): 17796-17804.

DOI：10.1364/OE.18.017796

We study the dynamics of a paired optical vortex (OV) generated by second-harmonic generation (SHG) using sub-picosecond pulses. By changing the position of a thin nonlinear crystal along the propagation direction, we observe a rotation of two vortices with changing separation distance. The dynamics is well explained by SHG with a beam walk-off, which introduces a contamination of zero-order Laguerre-Gaussian beam (LG(0)) together with topological charge doubling. The quantitative analysis indicates that the rotation angle of the OVs manifests the Gouy phase while the splitting provides the walk-off angle of the crystal. We also show that the subtraction of LG(0) is realized by the superposition of LG(0) with an anti-balanced phase in the pump.

• 出版日期2010-8-16