Sending femtosecond pulses in circles: highly nonparaxial accelerating beams

Abstract

We use caustic beam shaping on 100 fs pulses to experimentally generate nonparaxial accelerating beams along a 60° circular arc, moving laterally by 14 µm over a 28 µm propagation length. This is the highest degree of transverse acceleration reported to our knowledge. Using diffraction integral theory and numerical beam propagation simulations, we show that circular acceleration trajectories represent a unique class of nonparaxial diffraction-free beam profile which also preserves the femtosecond temporal structure in the vicinity of the caustic.

Arbitrary nonparaxial accelerating periodic beams and spherical shaping of light

“…We also show that our method of non-paraxial beam design is compatible with binary modulation and the generation of periodic (snake-like) propagation. Moreover, phase mask rotation extends the generation of non-paraxial circular beams into three dimensions, allowing us to also report the first observation of an accelerating wave generated to propagate along the surface of a sphere [10].We first note that although it is often believed that caustic descriptions are limited to geometrical optics, provided one considers scalar unidirectional propagation they can be straightforwardly included in wave optics through diffraction integral theory, without any paraxial approximation [9]. Considering firstly a two dimensional fold caustic propagating along z and accelerating along y we wish to determine the generating (Fourier) phase profile c ( )…”

“…Previous results using caustic design for non-paraxial accelerating beam generation, however, have been associated with non uniform illumination and small arc segments because phase modification to generate the caustic has been applied directly to the incident field [9].…”

Loss-proof self-accelerating beams and their use in non-paraxial manipulation of particles’ trajectories

“…These beams support bending of light beams to large angles, up to almost 180°, rather than the Airy beam that can only bend up to B10°before breaking the paraxial approximation. Such nonparaxial accelerating beams were demonstrated experimentally soon thereafter [15][16][17] . Likewise, several other types of accelerating beams, such as Weber and Mathieu beams, were discovered [18][19][20] , as well as nonlinear paraxial [21][22][23][24] and nonparaxial 16,25 accelerating beams, and even accelerating beams in curved space 26 .…”

Montage d’holographie numérique dynamique pour la nano-métrologie optique sans lentille

“…La restitution synthétique repose sur la théorie scalaire de la diffraction. Les deux principales approches sont la diffraction de Fresnel ou l'approche par spectre angulaire d'ondes planes [9,14].…”

“…Le montage d'holographie dynamique présenté peut être abordé et étudié à différents niveau de la formation (de la licence au master), et couvre le champ vaste de l'optique physique, de la théorie de l'information de la mé-trologie optique et de ses applications. A l'origine, ce banc expérimental a été réalisé à l'issus de travaux menés à l'institut FEMTO-ST concernant la mise en forme spatiale de faisceaux laser à impulsions ultracourtes par un SLM pour le micro-nano-usinage de matériaux [8][9][10][11].…”