Abstract

We demonstrate the possibility of generating a photonic nanojet with a helix shape (photonic nanohelix) at the diffraction of a Gaussian beam on a binary spiral axicon. We investigate the influence of the illuminating beam parameters on the shape and size of the generated photonic nanohelix by solving the Helmholtz equation using the finite element method. The simulated photonic nanohelix has depth of focus (DOF) of 2.21 μm ($3.49\lambda$) and FWHM of 304.5 nm ($0.48\lambda$), and the intensity maximum is 11.59 times higher than the incident beam maximum intensity. Using a near-field scanning optical microscope with a metal tip, it has been demonstrated that when we illuminate a binary spiral axicon with $\mathrm{NA}=0.5$ and depth of etching of 500 nm by a linearly polarized plane wave ($\lambda =633\mathrm{nm}$), the output beam is in the form of a photonic nanohelix of DOF $2.00\pm 0.25\mathrm{\mu }\mathrm{m}$ ($3.16\pm 0.39\lambda$) with FWHM $339\pm 5\mathrm{nm}$ ($0.54\pm 0.01\lambda$).

© 2016 Optical Society of America

Spatial control of photonic nanojets

Jinlong Zhu and Lynford L. Goddard
Opt. Express 24(26) 30444-30464 (2016)

Microaxicon-generated photonic nanojets

Yu. E. Geints, A. A. Zemlyanov, and E. K. Panina
J. Opt. Soc. Am. B 32(8) 1570-1574 (2015)

Sharper photonic nanojets generated by microspheres under higher-order radially polarized beam illumination

Zhenyu Xing, Xianghui Wang, Yuhang Fu, Wenjing Liu, Jierong Cheng, and Ming Zeng
Appl. Opt. 60(35) 10816-10824 (2021)

RDDA method for characterization of photonic nanojets

Mohammad Reza Ataii and Jafar Mostafavi Amjad
Appl. Opt. 63(10) 2543-2551 (2024)

Temperature-controlled photonic nanojet via VO₂ coating

Jia Hao Soh, Mengxue Wu, Guoqiang Gu, Lianwei Chen, and Minghui Hong
Appl. Opt. 55(14) 3751-3756 (2016)