Metalens have been recently introduced to overcome shortcomings of traditional lenses and optical systems, such as large volume and complicated assembly. As a proof-of-principle demonstration, we design an all-dielectric converging cylindrical metalens (CML) for working in long-wave infrared regions around 9 µm, which is made up of silicon-pillar on MgF dielectric layer. We further demonstrate the focusing effect of an orthogonal doublet cylindrical metalens (ODCM). Two CMLs are combined orthogonally and a circular focusing spot was demonstrated. This proves that within a certain size range, the focusing effect achieved by the ODCM is similar to that of a traditional circular metalens.
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http://dx.doi.org/10.1364/OE.414001 | DOI Listing |
Nanomaterials (Basel)
September 2023
CONAHCYT-Unidad Foránea Monterrey, Centro de Investigación Científica y de Educación Superior de Ensenada, Alianza Centro 504, PIIT, Apodaca 66629, Mexico.
Airy beams represent an important type of non-diffracting beams-they are the only non-diffracting wave in one dimension, and thus they can be produced with a cylindrical geometry that modifies a wavefront in one dimension. In this paper, we show the design of a cylindrical plasmonic metalens consisting of an array of nanoslits in a gold thin layer that modulates the phase of a Gaussian beam to generate an airy beam propagating in free space. Based on the numerical results, we show that it is possible to generate an airy beam by only matching the phase of wavefronts coming out from the array of gold nanoslits to the airy beam phase at plane z=0.
View Article and Find Full Text PDFPhotoacoustics
August 2023
Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Photoacoustic microscopy is advancing with research on utilizing ultraviolet and visible light. Dual-wavelength approaches are sought for observing DNA/RNA- and vascular-related disorders. However, the availability of high numerical aperture lenses covering both ultraviolet and visible wavelengths is severely limited due to challenges such as chromatic aberration in the optics.
View Article and Find Full Text PDFNanophotonics
September 2023
Institute of Optoelectronic Technology and the Centre for THz Research, China Jiliang University, Hangzhou 314423, China.
Using low-refractive-index metamaterials, we design a transmission-type radial-angular cylindrical vector beam generator. A high numerical aperture lens is constructed using an asymmetric meta-grating structure. The metamaterial vector beam generator and the meta-grating lens are physically cascaded to obtain the tight focusing characteristics of the vector light field.
View Article and Find Full Text PDFBased on the impedance-matching theory, a double-layer metal structure dynamical focusing cylindrical metalens with a stretchable substrate was designed at the operation frequency of 0.1 THz. The diameter, initial focal length, and NA of the metalens were 80 mm, 40 mm, and 0.
View Article and Find Full Text PDFIn recent years, researchers have made great progress in solving complex electromagnetic field computing problems by using deep learning methods. However, the approaches found in literature were devoted to solving the real-number problem of electromagnetic field calculations. For the complex number problem, there was no good solution.
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