We investigate omnidirectional reflection from higher-order gaps in one-dimensional photonic crystals. Moreover, we present a designing criterion for omnidirectional reflection from several distinct gaps simultaneously, using only a single photonic crystal with a constant period. We show that for practical values of photonic crystals parameters, several relatively large omnidirectional gaps may be obtained. As an example, we demonstrate an omnidirectional reflector that exhibits two distinct wide omnidirectional ranges at near-infrared wavelengths. This omnidirectional reflector that operates in several ranges of wavelengths may have various potential applications.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ao.46.003510 | DOI Listing |
Sci Adv
January 2025
Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
Electromagnetic wave propagation in three-dimensional (3D) space typically suffers omnidirectional scattering when encountering obstacles. In this study, we used Chern vectors to construct a topological heterostructure, where large-volume nonreciprocal topological transport in 3D is achieved. The shape of the cross section in the heterostructure can be arbitrary designed, and we experimentally observed the distinctive cross-shaped field pattern transport, nonreciprocal energy harvesting, and the remarkable ability of electromagnetic wave to traverse obstacles and abrupt structure changes without encountering reflections in 3D space.
View Article and Find Full Text PDFJ Acoust Soc Am
December 2024
Department of Computer Science, Acoustics Lab, Aalto University, P.O. Box 15400, FI-00076 Aalto, Finland.
ACS Nano
October 2024
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150000, China.
2-D carbon-based materials are well-known for their broadband absorption properties for efficient solar energy conversion. However, their high reflectivity poses a challenge for achieving efficient omnidirectional light absorption. Inspired by the multilevel structures of the flower, a Graphene Microflower (GM) material with gradient refractive index surface was fabricated on polymer substrates using the UV-intense laser-induced phase explosion technique under the synergistic design of the photothermal Marangoni effect and the fluid instability principle.
View Article and Find Full Text PDFLight Sci Appl
September 2024
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Black surface plays an important role in solar-thermal conversion systems and space optical systems. Despite the significant efforts in developing a black surface with strong broadband absorption, realizing scalable omnidirectional high absorption ultrablack surfaces remains challenging. Here, we report an ultrablack surface based on a structural black paint (SBP), realized by femtosecond (fs) laser fabrication of high aspect ratio microstructure mold followed by mold transferring on black paint coating.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!