Damghan University Press Journal of Holography Applications in Physics 2783-4778 6 3 2026 03 19 Holographic Generation of Bessel–Gaussian Vortex Beams Using a Ring-Apertured Fork Grating and Topological Charge Measurement via an Astigmatic Grating 31 51 2077 10.22128/jhap.2026.3169.1170 EN Somaye Fathollazade Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran 0009-0009-0899-9369 Saifollah Rasouli Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran; Optics Research Center, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran 0000-0003-2703-8925 Pouria Amiri Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran 0009-0007-7862-9748 Ahmad Absanov Abdusattarovich Engineering Physics Institute, Samarkand State University, Samarkand 703004, Uzbekistan Journal Article 2025 11 29 In this work, we introduce a holography-based method for generating Bessel–Gaussian vortex beams (BGVBs). The approach embeds a helical phase into a diffraction grating and then applies a ring-shaped transmission function. Embedding the helical phase converts the structure into a fork grating, while multiplication by the ring aperture ensures that the vortex beam produced in the first diffraction order evolves into a BGVB in the far field. The proposed holographic element was fabricated on a glass substrate using lithography, and illumination with a Gaussian beam of suitable waist generated a clear BGVB in the first diffraction order. The measured intensity profile shows excellent agreement with theoretical predictions. To determine the topological charge (TC), we employed an astigmatic grating with locally parallel grooves exhibiting second-order curvature. Introducing astigmatic aberration at an appropriate propagation distance produces elongated intensity fringes, and counting these fringes allows accurate determination of the TC. Numerical simulations and experimental measurements exhibit strong consistency, confirming the effectiveness of the proposed method. https://jhap.du.ac.ir/article_2077_5e96f5374fced097a233c35e30fc2ee8.pdf