Fig. 3: Photon density modes in bent waveguides.
a,b, Numerical simulations (Methods) of photon paths in a solid (no core) resin cylinder (radius 2.5 cm), with 10 rays (a) and 50 rays (b) plotted. c,d, The same simulations as in a and b with a 0.5-mm-radius, empty core and 10 rays (c) and 50 rays (d) that are detected at the resin structure exit facet (z = 5 cm). e, A schematic of the geometry tested in experiments to observe photon density mode guiding in a bent waveguide in a D-shaped cladding to allow visual access to the core. f, A lateral-view photograph of the 3D-printed waveguide structure. g, A numerical simulation (50 million rays) of the structure in f. h, The experimentally measured light profile of the structure in f.
