arXiv subjects

Mario Badás Aldecocea

Publications and source records attributed to Mario Badás Aldecocea.

4 recordsLinked to original sources

arXiv2026

Diffractive optical element for super-Gaussian beam shaping on intersatellite optical communications

Pointing jitter can significantly degrade the performance of intersatellite optical communication links. This work investigates diffractive optical beam shaping as a means of generating super-Gaussian profiles with reduced sensitivity to transmitter misalignment. Phase screens are designed using a Gerchberg--Saxton phase-retrieval algorithm and evaluated for different super-Gaussian orders. Lower-order profiles are reproduced accurately, whereas higher orders are increasingly limited by numerical discretization and finite-aperture effects. The practical implementation of the phase screens using fused-silica diffractive optical elements is assessed through sensitivity analyses of radial manufacturing resolution, phase quantization, phase-depth errors, and incident-beam wavefront aberrations. The results provide manufacturing tolerances and wavefront-quality requirements for preserving the desired beam shape.

physics.optics↗

arXiv2026

Super-Gaussian approximations for optimum far-field irradiance in intersatellite optical communications: coherent and incoherent beam shaping

Intersatellite optical communication links are strongly affected by transmitter pointing jitter, which stochastically modulates the received optical power and degrades communication performance. While adjusting the divergence of a conventional Gaussian beams can partially mitigate this effect, the optimum far-field irradiance distribution for maximizing link performance has not been formally derived. In this work, we introduce a variational formalism to determine the optimum far-field irradiance for an intersatellite link affected by pointing jitter. The flat-top beam is found to be the optimum beam shape for minimizing outage probability. In particular, it requires $\sim37,8\%$ of the power needed by a conventional Gaussian beam to achieve the same outage probability. However, the flat-top profile is discontinuous and physically unrealizable. To address this, we analyze a continuous family of super-Gaussian beam shapes that approximate the flat-top as the order increases. In addition, several coherent and incoherent beam shaping techniques are evaluated to assess their ability to reproduce the optimum irradiance distribution. The results show that these techniques can reduce the required transmitted power by up to $\sim50\%$ compared with conventional Gaussian beams.

physics.optics↗

arXiv2026

Annular beams for reliable intersatellite optical communications

Free-space optical communications (FSOC) are a key enabling technology for future high-capacity space-based networks. Particularly, the backbone of global communication relies on intersatellite optical links. In a previous study, the authors proposed a method to mitigate the impact of transmitter pointing jitter by using a superposition of orthogonally polarized Gaussian and higher-order Laguerre-Gaussian (LG) beams. In this study, we experimentally characterize the proposed system using a spiral phase plate (SPP) to generate higher-order annular beams. We demonstrate that such superpositions can be reliably generated in a realistic optical setup, quantify the associated beam-shaping errors and losses, and assess their impact on intersatellite optical communication performance. It is found that the proposed beam-shaping approach can still yield power savings on the order of 20% compared to a conventional Gaussian beam under the considered conditions.

physics.optics↗

arXiv2025

Quantum Key Distribution in the Iberian Peninsula

A promising use of quantum networking is quantum key distribution (QKD), which can provide information-theoretic security unattainable by classical means. While optical fiber-based QKD networks suffer from exponential loss, satellite-assisted quantum communication offers a scalable solution for long-distance secure key exchange. In this work, we propose and evaluate a satellite-based QKD setup covering the Iberian Peninsula, linking Madrid with Barcelona, Bilbao, and Lisbon. Our proposed setup uses a Low-Earth-Orbit (LEO) state-of-the-art satellite equipped with a spontaneous parametric down-conversion (SPDC) source to distribute entangled photon pairs to ground stations. Considering vibrations in the satellite, we optimize the beam waist to enhance the transmission probability and improve the secret key rate (SKR). Our results show that key rates sufficient for real-world applications, such as secure communication between hospitals, using hybrid classical-quantum protocols are feasible with existing protocols. Our results highlight the viability of near-term satellite-based QKD networks for national-scale secure communications.

quant-ph↗