Fig. 1. Schematics of the wavefront sensing. (a) Two channels on the SLM; C_T, test channel; C_R, reference channel; insets in (a) show the simulated interference patterns with various phase differences between the test and the reference channels: 0, π/2, π, and 3π/2. (b) SLM area division and scanning path of the test channel; (c) aberration correction mask loaded on the SLM; Fourier spectral profiles of the high-order Bessel beams (d) before and (e) after the correction.

Fig. 2. Schematic of the setup. BE, beam expander; HWP, half-wave plate; SLM, spatial light modulator; LB, laser block; ND filter, neutral-density filter; BS, beam splitter; Shutter, mechanical shutter; MO, microscope objective; CCD, CCD camera. Inset close to the SLM presents the phase pattern to generate the Bessel vortex beams; the corresponding 3D light fields at the focus area in the slide are presented in the inset close to MO.

Fig. 3. Correction of the high-order Bessel beams with vortex charge m = 6; the longitudinal intensity profiles along propagation (a) in simulation and in experiments (b) before and (c) after the correction; corresponding transverse intensity profiles at z = 250 µm in (d)–(f); (g) evolution of the main lobe size along the propagation.

Fig. 4. SEM photos of microtube structures fabricated with high-order Bessel beams. (a), (b) Before and (c), (d) after aberration correction; the scaling bars without notation represent 20 µm.

Fig. 5. Circularity measurement results of the microtube structures. (a) Outer rings and (b) inner rings.

Fig. 6. SEM photos of microtubes fabricated with high-order Bessel beams of different vortex charges.