Demonstration of vortical beams spectral stability formed in non-zero diffraction orders

Abstract

We provide a comparative analysis of vortical beams forming by a spiral phase plate and a binary fork diffraction grating. Intensity distributions formed by a diffractive optical element (DOE) have distortions whereas DOE's relief height is not corresponds to the wavelength of an incident beam. These distortions are numerically studied in this work. Different vortical beams are experimentally created and studied. The natural research is conducted with a spatial light modulator and with binary DOE. We experimentally show that fork binary DOEs are resistant to small deviation of incident beam wavelength and vortical beams are formed without any significant distortions.