Fig. 1. Experimental setup for the generation and characterization of second-harmonic STOVs. Fundamental STOVs of topological charges l = 1, 2 in the NIR are generated by a custom 4-f pulse shaper. G, grating; CL, cylindrical lens; L, lens; LBO, lithium triborate crystal; PRM, partial reflection mirror; CCD, charge-coupled device.

Fig. 2. (a) and (b) show experimental results of the green STOVs generated by the FW with topological charges of l = 1 and l = 2, respectively.

Fig. 3. Experimental setup for the generation and characterization of UV STOVs. DM, dichroic mirror.

Fig. 4. (a) Measured intensity profile and the corresponding diffraction lobe pattern of the UV-STOVs with topological charges l = 1, 2; (b) spectra of UV STOV, green Gaussian, and IR STOV.