Fig. 1. Schematic diagram of the longitudinal variation of polarization

Fig. 2. Schematic diagram of line focus with continuous variation of the polarization along the propagation distance^[43]

Fig. 3. Generation system of a Bessel beam whose polarization varies with propagation direction^[43]

Fig. 4. Generation system of a vector Bessel beam whose polarization varies with propagation^[44]

Fig. 5. Experimental setup of cascading spatial light modulator^[45]

Fig. 6. (a) Schematic diagram of a z-dependent polarizing device based on the metasurface; (b) Experimental setup of generating optical beam with polarization varying with propagation by metasurface^[46]

Fig. 7. Schematic representation of the experimental setup based on a Sagnac interferometer combined with the 4f system^[49]

Fig. 8. (a) Ggenerating device diagram of vector beams with longitudinally varying polarization based on the amplitude–phase joint modulation method; (b) Hologram of two-dimensional binary phase holographic grating^[50]

Fig. 9. (a) Generation and detection system diagram of vector optical beams with longitudinally varying polarization; (b) Schematic diagram of the dual-mode vector optical beam with cascaded variations of polarization in longitudinal direction^[51]

Fig. 10. Schematic of the theoretical configuration of reshaping the axial intensity distributions of quasi-Bessel beams^[40]

Fig. 11. Schematic diagram of spiral slit generating Bessel vortex beam^[54]