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TecnOPTO (Grupo de Tecnologias Ópticas y Optoelectronicas) is the Group of Optics and Optoelectronic Technologies at University Miguel Hernández, in Elche, Spain.
Our group develops different research lines, all within the field of Physical Optics and Optolectronics. We are located at the University Miguel Hernández, in the beautiful city of Elche, in Spain.
We enjoy doing research and working in projects with collaborators all over the world. We also enjoy teaching and involving our students in our projects.
Our last publication in Optics Express is entitled Liquid-crystal adaptive equivalent q-plate device with tunable topological charge.
In this work we present a novel compact and transmissive device useful to generate cylindrical vector beams (CVBs) of tunable topological charge. The device combines two adaptive spiral phase plates (ASPP) in orthogonal directions and a quarter-wave plate (QWP). Each ASPP relies on a specially designed circular transmission electrode with radial lines to generate a spiral phase upon addressing two voltages. The combination of two orthogonal ASPP allows imparting two independent spiral phases onto two orthogonal linear polarization states that are converted into circular states by the final QWP, thus efficiently realizing arbitrary CVBs.
By adjusting the four addressed voltages, the topological charges can be tuned to provide pure or hybrid CVBs with arbitrary topological charges. The device performance is analyzed in terms of the mapping relations between the Poincaré sphere and the higher-order Poincaré sphere. We find that it performs as a q-plate, but with the remarkable advantage of providing dynamic control of the topological charge in vortices and CVBs. Hence, we name it adaptive q-plate (AQ-plate).
This work was developed with Prof. Noureddine Bennis and his team at WAT (Wojskowa Akademia Techniczna), the Military Universiy of Technology, in Warsaw, Poland.
