Production of a broadband femtosecond optical vortex by use of a continuous spiral phase plate

In our work, a high-quality broadband femtosecond optical vortex is obtained by use of a continuous spiral phase plate (SPP) to modulate an ultrashort femtosecond (fs) laser with a broadband spectrum. The experimental results demonstrate that the continuous SPP is of good quality and that it can be used to efficiently produce a high-power fs optical vortex.