Poster
30 May 2022 Super-collimation with axisymmetric photonics
Darius Gailevičius, Indre Meskelaite, Edvinas Aleksandravicius, Martynas Peckus, Lina Grineviciute, Victor B. Taranenko, Kestutis Staliunas
Author Affiliations +
Conference Poster
Abstract
The laser beam shaping is a practical problem in both information transmission, detection and material processing. Many applications focus on beam intensity and phase control in the so-called near-field, but far-field phenomena in microsystems should be no less interesting. One new way to control far-field distributions is by applying what is called “supercollimation”. It can be observed in systems consisting of periodically arranged phase gratings made from concentric features that repeat along the optical axis. Supercollimation is defined as the transformation of a broad-angular-intensity profile beam into a very thin well-defined high-peak-intensity and low-divergence beam. Such a beam can be compared to a Bessel Beam, however, a sharp central peak does not appear in the near field, but on the contrary: in the far field. There is no simple way to understand how a supercollimated beams are formed because it does not occur with 1D or 2D periodic systems. What is clear is that it is a cascading process that requires multiple diffraction. In sufficiently, long structures, plane waves diffracted from 0-order to higher diffraction orders are diffracted back resonantly with a broadened angular distribution that can overlap with the zero-angle component in the spatial spectrum. Thus, the aim of this paper is to reveal how such a phenomenon can occur in periodic systems with rotational (axial) symmetry, such as photonic crystals and resonators with concentric gratings. Finally, I will discuss how to use the “broken” symmetry of asymmetric photonic crystals in interpreting this phenomenon in practical contexts.
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Darius Gailevičius, Indre Meskelaite, Edvinas Aleksandravicius, Martynas Peckus, Lina Grineviciute, Victor B. Taranenko, and Kestutis Staliunas "Super-collimation with axisymmetric photonics", Proc. SPIE PC12130, Metamaterials XIII, PC121301O (30 May 2022); https://doi.org/10.1117/12.2622113
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KEYWORDS
Photonics

Diffraction

Near field optics

Diffraction gratings

Near field

Photonic crystals

Collimators

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