Nowadays, dozens of anisotropic two-dimensional materials with diverse and highly tunable band structures have been discovered, exhibiting much richer optical functionalities, such as anisotropic absorption, luminescence, light detection, and hyperbolic polaritons, which provides a promising platform to explore and manipulate the light-matter interactions.
The image on the cover provides a visual rendering of the on-chip scheme for deterministic N-photon state generation in lithium niobate on insulator (LNOI) circuit, where deterministic parametric down-conversion (DPDC) and deterministic parametric up-conversion (DPUC) are realized through high-Q microring resonator and spiral waveguide, respectively.
An accurate quantitative phase imaging (QPI) technique based on pseudo-weak object approximation is proposed to achieve 3D quantitative measurements of both small-phase objects and large-phase objects by differential phase contrast without additional data acquisition.
Combining the special spatial distribution characteristics of the noble metal nanostructures with the special electrical-vector distribution characteristics of the azimuthal vector beam, the electrical nearfield intensity of the surface plasmonic mode localized near the noble metal nanostructures can be significantly improved, thereby achieving high sensitivity Raman examination. This vector light-field enhanced Raman spectroscopy is expected to be applied to trace detection.
It is believed that the next grand information revolution could be brought by an exotic class of devices whose operation is based on spins as the information carrier. To unveil the ultimate speed limit and energy efficiency of spintronic devices, one needs to understand the dynamics of spins in their host matrix. The emergent time-resolved terahertz technology has become not only our most advanced camera to film spins in action but also a versatile toolkit for manipulating spin states unachievable by conventional means.
The image illustrates the design concept of the pixelated Fabry-Perot (F-P) cavities. Structural color comes from the light interactions with sub-wavelength structures. Compared with conventional painting technology using chemical dyes, structural color has a broader range of technological applications. Among various color management technologies, F-P cavity represents an important solution for generating vivid colors. However, the fabrication of pixelated F-P cavities has mainly relied on the slow electron beam lithography process.
Periodic poling of resonant lithium niobate metasurfaces modifies their nonlinearity and enables tailoring the diffraction pattern of second harmonic generated by the metasurface. It adds another degree of freedom for designing nonlinear metasurfaces.
The small size and rich functions of metasurfaces have great potential for the development of new optical devices. The research group theoretically proved that the metasurface can realize the complete decoupling of the near-field and far-field functions of the same polarization at two working wavelengths. While the near-field encodes intensity patterns, the far-field functions can be holographic, focusing, and beam deflecting. The cover image shows that when a metasurface is illuminated by the light at 1064 nm and 1550 nm, the near-field intensity distribution displays the numbers 1064 and 1550, and the holographic pattern shows the emblem of Nanjing University and its landmark building North Building.
The image on the cover for Advanced Photonics Volume 5 Issue 1 illustrates a torus-knot configuration of a toroidal layer in the Hopf fibration and its vectorial properties of a photonic hopfion, which is controllably transported in free space. The image is based on original research presented in the article by Yijie Shen, Bingshi Yu, Haijun Wu, Chunyu Li, Zhihan Zhu, and Anatoly V. Zayats, “Topological transformation and free-space transport of photonic hopfions,” Adv. Photonics 5(1), 015001 (2023), doi: 10.1117/1.AP.5.1.015001.
High-pressure gas-jet optical shaping by four nanosecond-laser pulse generated blast waves. The computational study reveals that magnetic vortex acceleration delivers protons with maximum energies beyond 10 MeV when the ZEUS ultra-intense 45 TW, 25 fs laser pulse, interacts with the near-critical density, compressed profile, at the Institute of Plasma Physics & Lasers of the Hellenic Mediterranean University.
