Generation of Bessel vortex beams in the subterahertz range using reflecting diffractive optical elements. / Gerasimov, Vasily Valerievich; Osintseva, Natalya Dmitrievna; Pavelyev, Vladimir Sergeevich et al.
In: Computer Optics, Vol. 48, No. 3, 05.2024, p. 334-341.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Generation of Bessel vortex beams in the subterahertz range using reflecting diffractive optical elements
AU - Gerasimov, Vasily Valerievich
AU - Osintseva, Natalya Dmitrievna
AU - Pavelyev, Vladimir Sergeevich
AU - Agafonov, Andrey Nikolaevich
N1 - The work was done at the shared-use center \"Siberian Synchrotron and Terahertz Center\" and utilized the Novosibirsk free electron laser at the Budker institute of Nuclear Physics of the Siberian Branch of the RAS. The authors acknowledge core facilities \u201CVTAN\u201D (Novosibirsk State University) for access to the experimental equipment. The design of the diffractive optical elements was funded by a government project of the NRC \"Kurchatov Institute\".
PY - 2024/5
Y1 - 2024/5
N2 - In this work, we propose a simple method for generating Bessel vortex beams in the sub-terahertz (subTHz) range with the orbital angular momentum with l = 1 based on reflecting metal diffractive optical elements with a continuous helical microrelief. The elements are fabricated by micromilling in a polished duralumin substrate and by tin casting, and tested using a backward wave oscillator (wavelength λ = 855 µm). When using the micromilled element, Bessel vortex beams are shown to be generated and retain a Bessel intensity profile at a distance of 20 – 50 mm from the reflecting element, which is in good agreement with the results of numerical simulation. An experimental estimate of the energy efficiency of this element is 63%. When using elements made by tin casting, the vortex beams are generated with a distorted profile due to the presence of residual deformations of tin, which has plasticity. Due to their high conductivity, metallic reflecting elements can be used with high power density sub-THz radiation sources such as free electron lasers and gyrotrons.
AB - In this work, we propose a simple method for generating Bessel vortex beams in the sub-terahertz (subTHz) range with the orbital angular momentum with l = 1 based on reflecting metal diffractive optical elements with a continuous helical microrelief. The elements are fabricated by micromilling in a polished duralumin substrate and by tin casting, and tested using a backward wave oscillator (wavelength λ = 855 µm). When using the micromilled element, Bessel vortex beams are shown to be generated and retain a Bessel intensity profile at a distance of 20 – 50 mm from the reflecting element, which is in good agreement with the results of numerical simulation. An experimental estimate of the energy efficiency of this element is 63%. When using elements made by tin casting, the vortex beams are generated with a distorted profile due to the presence of residual deformations of tin, which has plasticity. Due to their high conductivity, metallic reflecting elements can be used with high power density sub-THz radiation sources such as free electron lasers and gyrotrons.
KW - Bessel beam
KW - diffractive optics
KW - reflecting diffractive optical element
KW - subterahertz range
KW - vortex beam
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85208423978&origin=inward&txGid=0236bbbafeccb11b81efa4b66c913d71
UR - https://www.mendeley.com/catalogue/bf6e95e2-4efb-3e0d-8cdc-620f60734ab0/
U2 - 10.18287/2412-6179-CO-1410
DO - 10.18287/2412-6179-CO-1410
M3 - Article
VL - 48
SP - 334
EP - 341
JO - Computer Optics
JF - Computer Optics
SN - 0134-2452
IS - 3
ER -
ID: 61120292