Castro-Ramos Jorge, Marciano-Melchor Magdalena, Marcelino-Aranda Mariana, Román-Hernández Edwin, Santiago-Santiago José Guadalupe, Silva-Ortigoza Gilberto, Silva-Ortigoza Ramón, Suárez-Xique Román, Zárate-Paz José Miguel
Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51 y 216, Tonantzintla, Puebla, C.P. 72000, Mexico.
J Opt Soc Am A Opt Image Sci Vis. 2013 Feb 1;30(2):177-88. doi: 10.1364/JOSAA.30.000177.
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.
