Fig. 1. Axial cross section schematic of the Bessel beam generated by an axicon

Fig. 2. Intensity distribution of beams transformed by axicon. (a) Intensity distribution in meridional plane; (b) 3D distribution; (c) section curve

Fig. 3. Intensity curves of central spot. (a) Curves in various wavelengths; (b) curves in various base angles

Fig. 4. Experimental configuration to sample the beam transformed by axicon

Fig. 5. Transverse sampling pictures in different distances with λ=0.6328 μm.（a）z=12 mm；（b）z=50 mm；（c）z=80 mm

Fig. 6. Transverse sampling pictures in different distances with λ=1.024 μm.（a）z=12 mm；（b）z=50 mm；（c）z=80 mm