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Updated: May 13, 2026

Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators
Published on: April 4, 2016
Wavefronts, caustics, and ronchigrams of a spherical wave reflected by a spherical mirror
Jorge Castro-Ramos1, Magdalena Marciano-Melchor, Mariana Marcelino-Aranda
1Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51 y 216, Tonantzintla, Puebla, C.P. 72000, Mexico.
Abstract:
The aim of the present work is twofold: first we obtain analytical expressions for both the wavefronts and the caustic associated with the light rays reflected by a spherical mirror after being emitted by a point light source located at an arbitrary position in free space, and second, we describe, in detail, the structure of the ronchigrams when the grating or Ronchi ruling is placed at different relative positions to the caustic region and the point light source is located on and off the optical axis. We find that, in general, the caustic has two branches: one is a segment of a line, and the other is a two-dimensional surface. The wavefronts, at the caustic region, have self intersections and singularities. The ronchigrams exhibit closed-loop fringes when the grating is placed at the caustic region.
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