Superposition of two optical vortices with opposite integer or non-integer orbital angular momentum

• Main Authors: Carlos Fernando Díaz Meza, Yezid Torres Moreno, Cristian Hernando Acevedo Cáceres
• Format: Article
• Language: English
• Published: Universidad Nacional de Colombia 2016-01-01
• Series: Ingeniería e Investigación
• Subjects: Optical vortices; superposition; topological charge; orbital angular momentum.
• Online Access: https://revistas.unal.edu.co/index.php/ingeinv/article/view/43948

This work develops a brief proposal to achieve the superposition of two opposite vortex beams, both with integer or non-integer mean value of the orbital angular momentum. The first part is about the generation of this kind of spatial light distributions through a modified Brown and Lohmann’s hologram. The inclusion of a simple mathematical expression into the pixelated grid’s transmittance function, based in Fourier domain properties, shifts the diffraction orders counterclockwise and clockwise to the same point and allows the addition of different modes. The strategy is theoretically and experimentally validated for the case of two opposite rotation helical wavefronts.