Multiple coherent OAM dispersive waves generation in dual concentric ring-core fiber

Light-carrying orbital angular momentum (OAM) has exhibited significant potential across a diverse array of fields. In several of these applications, broadband coherent OAM sources are essential for the functioning of optical systems. The emission of dispersive waves facilitates efficient energy transfer to distant spectral domains while preserving coherence between generated frequency components. In this work, we introduce a dual concentric-ring-core fiber design capable of generating two and four OAM dispersive waves (DWs) under conditions of anomalous dispersion and normal dispersion pumping, respectively. The physical phenomena underlying the spectral evolution are delved and each case is discussed separately. Our findings reveal that the locations and quantities of dispersive wave generation in both scenarios align with predictions derived from the corresponding phase matching conditions. This technique paves the way for the development of an efficient OAM supercontinuum source characterized by a high degree of coherence.