The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 25 2 2025 09 23 Investigation of dual Photonic Nanojets generated based on near-field diffraction from bifocal Fresnel zones Investigation of dual Photonic Nanojets generated based on near-field diffraction from bifocal Fresnel zones 299 309 3695 10.47176/ijpr.25.2.32071 FA Jafar Mostafavi Amjad Department of Physics, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran 0000-0002-0147-1299 Journal Article 2025 03 11 This article investigates the formation of Photonic Nanojets (PNJs) produced  by ring-shaped structures with a Fresnel-like geometric distribution using the Reduced Discrete Dipole Approximation (RDDA) method. Three structures with geometric distributions of regular rings, rings aligned with Fresnel zones, and bifocal Fresnel zones have been studied. The formation and optimization of dual PNJs (two simultaneous photonic nanojets) along the propagation axis have been found by dividing the Fresnel zones into two regions, as well as by adjusting the average focal length favg and the disk radius R, which leads to a change in the number of primary Fresnel zones in each divided region. The Best decoupled and confined dual PNJs from the proposed structures have been identified for several optimized states. This article investigates the formation of Photonic Nanojets (PNJs) produced  by ring-shaped structures with a Fresnel-like geometric distribution using the Reduced Discrete Dipole Approximation (RDDA) method. Three structures with geometric distributions of regular rings, rings aligned with Fresnel zones, and bifocal Fresnel zones have been studied. The formation and optimization of dual PNJs (two simultaneous photonic nanojets) along the propagation axis have been found by dividing the Fresnel zones into two regions, as well as by adjusting the average focal length favg and the disk radius R, which leads to a change in the number of primary Fresnel zones in each divided region. The Best decoupled and confined dual PNJs from the proposed structures have been identified for several optimized states. https://ijpr.iut.ac.ir/article_3695_af1b5754061ebbd4412adfb34c8d3534.pdf