We measured the supernumerary spacing parameter of the first- and second-order rainbows of two glass rods, each having an approximately elliptical cross section, as a function of the rod's rotation angle. We attribute large fluctuations in the supernumerary spacing parameter to small local inhomogeneities in the rod's refractive index. The low-pass filtered first-order rainbow experimental data agree with the prediction of ray-tracing-wave-front modeling to within a few percent, and the second-order rainbow data exhibit additional effects that are due to rod nonellipticity. (C) 2001 Optical Society of America.
Adler, Charles L.; Phipps, David; Saunders, Kirk W.; Nash, Justin K.; and Lock, James A., "Supernumerary Spacing of Rainbows Produced by an Elliptical-Cross-Section Cylinder. II. Experiment" (2001). Physics Faculty Publications. 89.
Adler, Charles L., David Phipps, Kirk W. Saunders, Justin K. Nash, and James A. Lock. "Supernumerary Spacing of Rainbows Produced by an Elliptical-Cross-Section Cylinder. II. Experiment." Applied Optics 40 (2001): 2535-2545.
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