Experimental study on generation of perfect vortex beams with an orthogonal grating

This study demonstrates an alternative approach to address the overlap of different-order perfect vortex beams(PVB), which occurs when computer-generated holography (CGH) on a spatial light modulator (SLM) is used for PVB generation. The overlap between the 0th order and the ±1st order diffraction modes on the Fourier plane can be resolved by inserting an orthogonal grating between the axion and the Fourier lens. It is also experimentally verified that the radius of positive first-order perfect vortex beam remains effectively constant (ΔR/R < 1%).