A research group dedicated to study the fundamental physical properties of light beams.

**Optical Forces in Optical Beams with Space-Variant Polarization**

Optical trapping and manipulation rely on understanding the dynamical properties of light, such as energy, momentum and angular momentum. In particular, the spin momentum density has recently attracted attention for its potential applications in the manipulation of nanoparticles and the excitation of single atoms.

We characterize the spin and orbital momentum densities in the superposition of two paraxial vortex beams with orthogonal polarizations. Our goal is to understand the interplay between the two types of momentum densities. In addition, it provides a practical model that can be implemented experimentally to demonstrate the spin part of the optical energy flows.

Related publications:

- Dynamics of polarization singularities in composite optical vortices
- Measuring topological charge using Stokes parameters
- Orbital angular momentum of optical vortices from power measurements and the cross-correlation function
- Measurement of orbital angular momentum with an off-axis superposition of vector modes
- Internal energy flows in composite optical vortices

**Geometric Phase Polarimetry**

If light travels a set of optical elements, it acquires a dynamic and a geometric phase. The former is produced by the optical path length and the latter by the evolution of the polarization state on the Poincaré sphere. The goal of this project is to manipulate space-variant polarized beams by shaping the polarization distribution according to the response of the optical system.

Related publications:

- Analysis of the geometric phase produced by homogeneous and inhomogeneous Jones matrices for applications in space-variant polarized beams
- Geometric phase morphology of Jones matrices

**Quantum Optical Coherence Tomography**

Quantum-optical coherence tomography is a novel imaging technique capable of measuring the internal structure of a sample by employing nonclassical states of light, such as entangled photon pairs. Our goal is to improve this technique to the level of real medical applications.

Related publications:

- Quantum optical coherence tomography using three time-energy entangled photons
- Coherence measurements with the two-photon Michelson interferometer
- Quantum-optical coherence tomography with collinear entangled photons

**Terahertz optical elements fabricated by 3D-printing technology**

In this project, we work in the design, fabrication and characterization of q-plates for the generation of structured terahertz beams.

Related publications:

- 3D printed terahertz q-plate for vectorial beam generation
- Pancharatnam-Berry phase optical elements fabricated by 3D printing for shaping terahertz beams
- q-plate for the Generation of Terahertz Cylindrical Vector Beams Fabricated by 3D Printing