Fig. 1. Schematic for generation of Bessel beams under different incident conditions. (a) Gaussian beam; (b) donut beam

Fig. 2. Structural diagram of designed lens group

Fig. 3. Simulation results of output beams after each device. (a) Bessel beam emerging from A1; (b) donut beam emerging from L; (c) Bessel beam emerging from A2

Fig. 4. Schematic of experimental setup

Fig. 5. Sectional spots and beam propagation maps. (a) Collimating Gaussian beam; (b) Bessel beam emerging from A1; (c) donut beam emerging from L; (d) final Bessel beam emerging from A2

Fig. 6. Final results of whole sysytem. (a) Beam propagation map and sectional spots; (b) curve of full width at half maximum