A vector-ray tracing (VRT) model is employed to simulate optical caustic structures [in terms of rainbow and hyperbolic umbilic (HU) fringes] in the secondary rainbow region of light scattering from oblate droplets. The changes of the rainbow fringe and HU fringe in response to shape deformation of oblate droplets are investigated and the curvature of the rainbow fringe is calculated. Then the location of cusp caustics is calculated from VRT simulations and compared with analytic solutions.
© 2013 Optical Society of America
Original Manuscript: September 2, 2013
Manuscript Accepted: September 25, 2013
Published: October 31, 2013
Haitao Yu, Feng Xu, and Cameron Tropea, "Simulation of optical caustics associated with the secondary rainbow of oblate droplets," Opt. Lett. 38, 4469-4472 (2013)