Multilevel Spiral Axicon for High-Order Bessel–Gauss Beams Generation

Abstract

This paper presents an efficient method to generate high-order Bessel–Gauss beams carrying orbital angular momentum (OAM) by using a thin and compact optical element such as a multilevel spiral axicon. This approach represents an excellent alternative for diffraction-free OAM beam generation instead of complex methods based on a doublet formed by a physical spiral phase plate and zero-order axicon, phase holograms loaded on spatial light modulators (SLMs), or the interferometric method. Here, we present the fabrication process for axicons with 16 and 32 levels, characterized by high mode conversion efficiency and good transmission for visible light (λ = 633 nm wavelength). The Bessel vortex states generated with the proposed diffractive optical elements (DOEs) can be exploited as a very useful resource for optical and quantum communication in free-space channels or in optical fibers.

Direct search method of double-layer diffractive optical elements

“…Their presence is essential in facilitating quality improvement 1 – 5 Given their inherently diffractive nature, these elements are known to introduce extra stray light during the imaging process, posing a significant challenge in reducing their occurrence 6 , 7 . Throughout the evolution of optics, one of the key challenges in the utilization of DOEs is mitigating the stray light generated by them.…”

Determining Topological Charge of Bessel-Gaussian Beams Using Modified Mach-Zehnder Interferometer

“…Also, BG beams contribute significantly to optical tweezers [17] and high-resolution imaging [18]. For the progress of potential applications, various efficient methods for BG beam generation have been reported [19][20][21][22][23][24][25][26][27][28][29][30][31].…”

“…These approaches utilize axicon holograms encoded onto a spatial light modulator (SLM). For the generation of higher-order BG beams, SLM encoded with a combined spatial phase plate (SPP) and axicon phase-only hologram have been utilized [23,24]. The utilization of metasurfaces has also been reported [25].Fabry-Perot resonator-based BG beam generation has also been reported [26,27].In the resonator, constructive and destructive interferences occur between the standing waves, resulting in a circular, symmetric spatial-frequency spectrum.…”

Generating scalar and vector modes of Bessel beams utilizing holographic axicon phase with spatial light modulator

“…Furthermore, a spatial light modulator (SLM) encoded with tunable axicon hologram has been utilized to generate a zero-order BG beam [22,23]. In some of the studies, an SLM encoded with combined spatial phase plate (SPP) and axicon phase-only hologram and spiral phase holograms have been used for higherorder BG beam generation [24][25][26]. Metasurfaces have also been reported for higher-order BG beam generation [27].…”