Figure 2

Schematic of measurement setups for studies on the ability of the fabricated BnVPM on the generation of optical vortex beams in a broadband infrared wavelength range. Setups for observing doughnut-like intensity distribution (a); for observing the phase singularity and determining the topological charge of the generated OVBs using astigmatic transformation (b); and Mach–Zehnder interferometer configuration (c).