Abstract
Much attention has been paid to photonic applications based on periodic media. Meanwhile, quasi-periodic and disordered media have extended the research domain and provided additional novelties for manipulating and controlling light propagation. This review article attempts to highlight the benefits of symmetry reduction in highly symmetric periodic photonic media, and applies the concept of chirality to all-dielectric materials arranged in special orders. Two-dimensional periodic structures known as photonic crystals (PCs) are highly symmetric in terms of structural patterns, due to the lattice types and shape of the elements occupying the PC unit-cell. We propose the idea of intentionally introducing reduced-symmetry, to search for anomalous optical characteristics so that these types of PCs can be used in the design of novel optical devices. Breaking either translational or rotational symmetries of PCs provides enhanced and additional optical characteristics such as creation of a complete photonic bandgap, wavelength demultiplexing, super-collimation, tilted self-collimation, and beam deflecting/routing properties. Utilizing these characteristics allows the design of several types of photonic devices such as polarization-independent waveguides, wavelength demultiplexers, beam deflectors, and routers. Moreover, reducing the symmetry in the PC unit-cell scale produces a novel feature in all-dielectric PCs that is known as chirality. On the basis of above considerations, it is expected that low-symmetric PCs can be considered as a potential structure in photonic device applications, due to the rich inherent optical properties, providing broadband operation, and being free of absorption losses.
Highlights
TO PHOTONIC CRYSTALS WITH REDUCED-SYMMETRYIn order to exploit novel optical properties of light, it is essential to convert a medium with a homogeneous refractive index into a periodically modulated one
We propose the idea of intentionally introducing reduced-symmetry, to search for anomalous optical characteristics so that these types of photonic crystals (PCs) can be used in the design of novel optical devices
We numerically proved that keeping the direction of incident light illumination as the same, designed 2D PCs with low-symmetry and its mirror image may optically respond in different manners at certain frequencies
Summary
In order to exploit novel optical properties of light, it is essential to convert a medium with a homogeneous refractive index into a periodically modulated one. Random and disordered PCs do not have any spatial symmetry property, quasi-periodic structures possess a reduced symmetry characteristic; these types of periodic structures have high rotational symmetry and, anomalous characteristics may arise, especially in transmission spectra and photonic band gaps [30]−[33]. Due to the high rotational symmetries of quasi-crystals, their forbidden band gaps and light transport properties are superior to regular PCs [34]−[40]. Using these types of PC designs, unique properties appear in transmission, reflection, refraction, localization, radiation of photons, symmetry in Fourier space, nonlinear optical, and diffraction characteristics. The last two sections (Sections 5 and 6) include discussions of potential applications, future research directions, and the conclusions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the European Optical Society-Rapid Publications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
