Experimental validation of the FRISP method with a SiO₂ micro sphere with a diameter of 11 μm. The normalized intensity distribution of a Photonic nanojet generated by a SiO₂ micro sphere along the propagation axis a) simulated and b) measured by an optical microscope. c) Comparison of the intensities along the centerline of the simulation a) (red) and the experiment b) (blue).