Asymmetric Shaping for Ultrafast Elliptical Bessel-like Beams

The generation of an elliptical Bessel–Gauss beam has become a topic of interest in ultrafast laser processing of transparent materials because of its nearly non-diffractive elliptical central core. These beams can show potential in generating anisotropic structures down to the nanoscale and in prod...

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Bibliographic Details
Main Authors: Niladri Ganguly, Rajeev Dwivedi, Ciro D’Amico, Razvan Stoian
Format: Article
Language:English
Published: MDPI AG 2023-06-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/10/6/651
Description
Summary:The generation of an elliptical Bessel–Gauss beam has become a topic of interest in ultrafast laser processing of transparent materials because of its nearly non-diffractive elliptical central core. These beams can show potential in generating anisotropic structures down to the nanoscale and in producing asymmetries in the induced fields of thermo-mechanical constraints relevant for material structuring. However, maintaining the central core ellipticity is a challenge that requires further analysis, notably in the propagation behavior of phase anisotropies during the conical interference. This paper presents the controlled generation and propagation of a highly elliptical Bessel–Gauss beam using asymmetric phase-modulation technique. The study involves engineering different asymmetric phase holograms and analyzing their performances in terms of the non-diffractive property and uniformity of the generated beams. We indicate the presence in specific cases of diffraction and its influence on the invariance of the beam shape. The simulation results are in excellent agreement with the experimental results, which verifies the accuracy and reliability of our approach.
ISSN:2304-6732