LED-based chromatic and white-light vortices of fractional topological charges

• Published in: Optics communications 2021-04, Vol.485, p.126732, Article 126732
• Main Authors: Zhang, Yuanying, Guo, Haoxu, Qiu, Xiaodong, Lu, Xiancong, Ren, Xuechang, Chen, Lixiang
• Format: Article
• Language: English
• Subjects: Gaussian–Schell model; Propagation dynamics; White-light vortices
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2020.126732

Based on an LED light source, we present an experimental scheme to produce chromatic and white-light optical vortices carrying fractional topological charges. In theory, we develop a general formula to simulate the propagation dynamics of such fractional chromatic and white-light vortices based on the eigenmode decomposition of orbital angular momentum within the Gaussian–Schell model. In the experiment, for the generation of the chromatic and white-light optical vortices, we use a phase-only spatial light modulator to prepare the desired holographic gratings and a prism to compensate for the dispersion for three primary colors (red, green, and blue). The experimental observations, e.g., the seal-healing effect of dislocation lines, are in good agreement with the simulation results. The present work extends the studies of fractional optical vortices not only from highly coherent to partially coherent region but also from monochromatic to chromatic (white-light) source, which may find potential applications in LED-based visible light communication and optical displaying. •The general propagation formula for the partially coherent beam carrying superposed/fractional vortices is derived.•The LED-based vortices carrying fractional topological charge are generated, and their propagating dynamics are studied.•The research on the generation of LED-based vortex and its propagation characteristics will have potential in the field of optical communications.