Fig. 5. Accelerating beam with circular trajectory. (a) One-dimensional optical field evolution and inset in upper right corner is schematic of generating caustics, where solid curve represents accelerating beam with circular trajectory, solid lines without arrows represent cluster of rays, and dotted line represents rear focal plane of lens; (b1)-(b3) numerical intensity distributions at different distances: ξ=10,35,50; (c1)-(c3) experimental intensity distributions at different distan