Searcharxiv⌕ Search

arXiv subjects

D. Sánchez-de-la-Llave

Publications and source records attributed to D. Sánchez-de-la-Llave.

9 recordsLinked to original sources
arXiv2026

From Rings to Top-Hat beams

We present the exact analytical paraxial propagation of structured light beams that transition from Ring annular profiles to top-hat intensity distributions. The initial field is defined as a superposition of a Gaussian-weighted power-law core and a singular inverse-quadratic modulation term, both carrying an azimuthal phase factor. By solving the Fresnel diffraction integral in cylindrical coordinates, we obtain exact closed-form expressions for the propagated field at arbitrary planes. The paraxial evolution is shown to be governed by a Cauchy-Riemann beam term and an infinite series of modified Bessel functions of the second kind weighted by an azimuthal phase factor. This analytical framework demonstrates how tuning the source parameters enables a continuous transition from ring-dominated annular profiles to uniform top-hat beams. For the fundamental mode ($l=0$), the singular component fills the central intensity null, producing a flat transverse plateau.

physics.optics↗
arXiv2026

Paraxial beam propagation from Airy-type initial conditions via the Operator Method

We employ quantum mechanical operator techniques to solve the equations of $(1+1)D$ and $(2+1)D$ for paraxial waves with initial conditions defined by Airy-type functions. In the first part, we find the expressions of $(1+1)D$ optical beams, considering initial conditions such as Airy, Airy-truncated, and Airy-Gaussian functions. Subsequently, we extended the analysis to $(2+1)D$ optical beams with initial conditions generated by the product of two Airy, two Airy-truncated and two Airy-Gaussian functions, providing a comprehensive study of multidimensional Airy beam propagation. To validate our theoretical derivations, we present both theoretical and experimental intensity profiles, showing excellent agreement between the two, illustrating the physical characteristics of these beams. Although these solutions have previously been obtained via the diffraction integral and thoroughly studied, the primary goal here is to demonstrate that the optical fields can be derived using quantum mechanical operator methods. Finally, we remark that this alternative approach offers an elegant and powerful framework for analyzing paraxial wave propagation.

physics.optics↗
arXiv2024

Poynting vector for Cauchy-Riemann beams

We present a detailed derivation of the Poynting vector for Cauchy-Riemann beams propagating in free space considering a Gaussian modulation with $g \in \mathbb{C}$. The effect generated by this Gaussian modulation is a compression-expansion of the intensity distribution. It is shown that the parameter $g$ can reverse the direction of energy flux and eliminate the radial component, resulting in a purely azimuthal field. Additionally, we validate our analytical results through experimental verification.

physics.optics↗
arXiv2024

Asymmetric Cauchy-Riemann Beams

We investigate, theoretically and experimentally, the evolution of a paraxial beam propagating in free space when its initial transverse structure is characterized by an asymmetric Gaussian modulation combined with an entire function. Utilizing a quantum optics operator approach, our study specifically examines the effects of parameter variations within the Gaussian modulation on two entire functions: the Bessel function and the Airy function. Through this investigation, we aim to elucidate how these parameter variations influence the beam's propagation dynamics and the role played by the asymmetry of the Gaussian modulation in the propagation of such paraxial beams. Additionally, we provide a comprehensive method for computing the propagated field under these conditions.

physics.optics↗
arXiv2023

Cauchy-Riemann beams in GRIN media

We investigate the propagation characteristics of Cauchy-Riemann beams in gradient-index media. Our study reveals two key findings: a) the preservation of their form during propagation, and b) surprisingly, the feasibility of obtaining the fractional Fourier transform for any arbitrary entire function. We provide an explicit and straightforward expression for this transform. Additionally, our results contribute to a deeper understanding of the behavior of Cauchy-Riemann beams in complex media, offering insights that may have implications for various applications in optics and wave propagation.

physics.optics↗
arXiv2023

Cauchy-Riemann beams

By using operator techniques, we solve the paraxial wave equation for a field given by the multiplication of a Gaussian function and an entire function. The latter possesses a unique property, being an eigenfunction of the {\it perpendicular} Laplacian with a zero eigenvalue, a consequence of the Cauchy-Riemann equations. We demonstrate, both theoretically and experimentally, the inherent rotation of this field during its propagation. The explanation for these rotations lies in the utilization of the quantum (Bohm) potential. The simplicity of this outcome reveals promising prospects: it enables the analytical deduction of the Fraunhofer or Fresnel diffraction pattern. In essence, this means that obtaining the Fresnel or Fourier transform of a function satisfying the Cauchy-Riemann equations becomes a straightforward task.

physics.optics↗
arXiv2021

Generation of Talbot-like fields

We present an integral of diffraction based on particular eigenfunctions of the Laplacian in two dimensions. We show how to propagate some fields, in particular a Bessel field, a superposition of Airy beams, both over the square root of the radial coordinate, and show how to construct a field that reproduces itself periodically in propagation, i.e., a field that renders the Talbot effect. Additionally, it is shown that the superposition of Airy beams produces self-focusing.

physics.optics↗
arXiv2018

Conversion of any finite bandwidth optical field into a shape invariant beam

We discuss a method to transform any optical field, with finite frequency bandwidth, into a shape invariant beam with transverse scaling, dependent on the propagation distance. The method consists in modulating the field with a quadratic phase of appropriate curvature radius. As a particular application, we employ the method to extend the existence region of a finite non-diffracting field to an unbounded domain.

physics.optics↗