Figure 9

Radial intensity distribution, where λ = 0.1133 m, z = 100λ, r_n = λ and \(\frac{A\lambda }{4\pi z}=1\). l = 0, 1, 2 denote the OAM modes generated by UCA_1×∞ and J₀, J₁, J₂ denote the absolute value of 0, 1, 2 order first kind Bessel function respectively.