Polarization-correction device with liquid crystals for quantum-key-distribution satellite systems

Jimenez-Girela, A.; Merino-Pérez, D.; Campos-Jara, A.; Socas Negrín, J.; Parejo, P. Garcia; Álvarez-Herrero, A.
Referencia bibliográfica

Physical Review Applied

Fecha de publicación:
6
2025
Número de autores
6
Número de autores del IAC
1
Número de citas
0
Número de citas referidas
0
Descripción
In this paper, we present a device, designed to be used in a space payload, capable of correcting any arbitrary polarization state. The device consists of a set of three liquid-crystal variable-retarder (LCVR) cells, in which by selecting the appropriate values of the voltage to be applied in each of them, it can correct the undesirable effects. In particular, the degradation effects of the polarization states, such as ellipticity and rotation with respect to the reference system, are compensated. Among many other potential applications, this device has been conceived to be used in quantum-key-distribution (QKD) intersatellite link or satellite-ground polarization-coding protocols as a polarization-correction device (PCD). To demonstrate that these effects are corrected, we have carried out an experiment in which we have tested how the BB84 protocol states are compensated after being strongly perturbed, achieving polarization extinction ratio (PER) values around 39 dB. Our solution offers the advantage of being small and mechanism free, being the ideal solution to be implemented in small satellites. These satellites are the core to be used in future constellations required for a global quantum communications network.