Fig. 1. OAM of a STOV wavepacket with phase singularities embedded in the x–z and y–z domains with varying scaling factors. (a) OAM projection in the y-direction and x-direction when w_y or w_x is fixed. (b) Magnitude of OAM with a changing w_x and w_y. The dashed lines correspond to results shown in (a1) and (a2). (c) Orientation of OAM in the x–y plane with varying w_x and w_y. Adapted from Ref. [1].

Fig. 2. Spatiotemporal intensity and phase profile of STOV wavepackets with phase singularities embedded in the x-t and x′-t domains. The angle difference between the x- and x′-axes changes from 0 to π in an interval of π/4 (from left to right). (a) Intensity isosurface plot at 15% and 50% of the intensity maximum. (b) Phase distribution on the 15% intensity isosurface plot. (c) Intensity isosurface plot (15%) in the x–y plane. Adapted from Ref. [1].

Fig. 3. Iso-intensity of simulated partially coherent tilted vortices in (a) the x-t view and (b) the y-t view. The coherence time, τ_C = 186 fs, is overlayed in one section to highlight the typical length of the intensity fluctuations and vortices. (c) A small region of the same realization shown to highlight the random vortex tilt path. Adapted from Ref. [2].

Fig. 4. (Upper) (a) Experimental setup. BS, beam splitter; CL, cylindrical len with focal length f₁ = 100 mm; SLM, spatial light modulator; M, mirror; SL, spherical lens with focal length f = 300 mm; distances z₁ = 200 mm and z₂ = 200 mm. (b) SLM spiral phase map. (c) Spectrum of ASE light source. (Lower left) (a), (b) Simulated interference patterns at two reference delays of 30 separations. (c) 3D trace of the singularity. (Lower right) (a), (b) Experimental interference patterns at two reference delays showing moving singularity indicated by arrows. (c) Plot of vortex singularity points position versus delay. Adapted from Ref. [2].

Fig. 5. Simulation of Airy-STOV wave packet of topological charge l = 1. (a) Normalized intensity profile and (b) phase profile. Adapted from Ref. [3].

Fig. 6. Phase singularity temporal shift as a function of GVD. Adapted from Ref. [3].

Fig. 7. Experimental setup and corresponding results for the generation and characterization of UV STOVs using the SFG process. Adapted from Ref. [5].

Fig. 8. Schematic of directional power transfer and omnidirectional information transmission based on the proposed ASTCM and the measured normalized spectrum distribution. Adapted from Ref. [7].

Fig. 9. Conceptual depiction of the implementation of the cascaded LC-holographic encryption, along with the corresponding experimental setup and results. Adapted from Ref. [8].