Generation of optical vortices by fractional derivative

• A new method of vortex generation using the two-dimensional fractional derivative is presented.
• Vortices from Gaussian and Hermite–Gaussian distributions are obtained.
• A regular lattice of optical vortices is obtained starting from an interference pattern.
• The method can be used to design a filter for vortex generation.

This paper presents a new method of vortex generation using two-dimensional fractional derivative. The characteristics of vortices obtained using this method from Gaussian and Hermite–Gauss distributions are presented. Changing the parameters of fractional derivative such as the fractional order, r, and the direction, θ, the positions of the vortex centers can be changed. The method can be used to design a filter for vortex generation. The analysis of an experimental vortex pattern using fractional derivative is also demonstrated.