Topological lightwave synthesis based on plasma hologram

点击翻译按钮获取中文摘要

We performed forward four-wave mixing in plasma created by highly intense optical vortex, so as to transfer the total angular momentum of the optical vortex to the diffracted beam. A laser used was a picosecond Nd:YAG laser (wavelength : 1064nm, pulse width : 20ps, pulse energy : 1~5mJ), and its output was converted to optical vortex with a total angular momentum of 1 by a spiral phase plate. The optical vortex and its reference pulses were spatially overlapped on a target silica glass, thereby forming the plasma grating. Self-diffracted output with an annular intensity profile was then observed. Furthermore, self-diffracted output energy was almost proportional to the cube of the optical vortex energy. These results evidenced that the total angular momentum was transferred from the optical vortex to the diffracted output through four-wave mixing process in plasma grating.