Casimir interaction driven by hyperbolic polaritons.

Casimir interaction is an intriguing phenomenon that is induced by electromagnetic quantum fluctuations, which dominates the interaction between microstructures at small separations and is essential for micro- and nano-electromechanical systems (MEMS and NEMS). However, Casimir interaction driven by hyperbolic polaritons remains an unexplored frontier. In this work, we investigate the Casimir interaction between natural hyperbolic material hexagonal boron nitride from the perspective of force distribution with different optical axis orientations for the first time.

A multi-dimensional photodetector based on an α-MoO grating and graphene.

Integration of multi-dimensional optical information enhances the recognition and anti-interference capabilities of the detection system, allowing for better adaptation to complex environments. Therefore, this technology represents a crucial developmental pathway for the future of infrared optical detectors. In this study, a dual-band polarization photodetector based on a two-dimensional α-MoO grating structure is proposed.

A tungsten-based metamaterial emitter for solar thermophotovoltaic systems.

Solar thermophotovoltaic systems are capable of showing efficient photoelectric conversion and are expected to surpass the Shockley-Queisser limit, owing to the spectrum-selective functionality of metamaterial selective emitters. Generally, metamaterial emitters are manufactured from multifarious materials, which also makes their manufacturing process complicated. Here, we propose a tungsten-only emitter composed of two rectangular bars with different widths and heights arranged in a cruciform structure, featuring a rectangular cavity at the top.

Coupling polaritons in near-field radiative heat transfer between multilayer graphene/vacuum/α-MoO/vacuum heterostructures.

Both materials and structures can significantly affect radiative heat transfer, which is more pronounced in the near-field regime of two-dimensional and hyperbolic materials, and has promising prospects in thermophotovoltaics, radiative cooling, and nanoscale metrology. Hence, it is important to investigate the near-field radiative heat transfer (NFRHT) in complicated heterostructures consisting of two-dimensional and hyperbolic materials. Recent studies have reported that adding vacuum layers to multilayer structures can effectively enhance the NFRHT.

Enhanced near-field radiative heat transfer between core-shell nanoparticles through surface modes hybridization.

Core-shell nanoparticles (CSNPs) are widely used in energy harvesting, conversion, and thermal management due to the excellent physical properties of different components. Because of the synergistic interaction between the core and the shell, the thermal radiative properties are expected to be further enhanced. In this work, we achieve near-field radiative heat transfer (NFRHT) enhancement between SiC@Drude CSNPs.

Optical axis-driven tunable Brewster effect in anisotropic materials.

The Brewster effect, which is known as a notable physical law, has promising prospects in perfect absorption and angular selectivity transmission. The Brewster effect in isotropic materials has been investigated extensively in previous works. However, the research on anisotropic materials has been rarely carried out.

Gradient index effect assisted anisotropic broadband absorption in α-MoO metamaterial.

As an excellent natural hyperbolic material (HM), - has a larger hyperbolic bandwidth and longer polariton lifetime than other HMs, which makes it an ideal candidate for broadband absorbers. In this work, we theoretically and numerically investigated the spectral absorption of an - metamaterial using the gradient index effect. The results show that the absorber has an average spectral absorbance of 99.

Pattern-free solar absorber driven by superposed Fabry-Perot resonances.

Solar absorbers, which harvest solar irradiation in the form of heat, have promising prospects in electricity, heating, desalination, and energy storage. However, in previous work, absorbers are usually designed as nanostructures involving photolithography to obtain a superior spectral absorption performance, which inevitably increases the cost and complexity of fabrication. Here, we propose a pattern-free absorber consisting of the TiN-SiO-based multilayer structure for effective solar energy utilization.

Comparative analysis of two models for the optical response of a thin slab: a film of finite thickness a surface current sheet.

An accurate description of the electromagnetic properties of materials is fundamental to optical and electric devices. As a current research hotspot, thin slabs generally are modeled as a film of finite thickness with a dielectric function. However, inspired by two-dimensional materials, thin slabs can be regarded as surface current sheets with conductivity.

Epsilon-near-zero characteristics of near-field radiative heat transfer between α-MoO slabs.

Epsilon-near-zero (ENZ) materials, which manifest a wealth of exotic optical characteristics, have attracted significant research interest in recent years. However, these characteristics have rarely been considered in the study of near-field radiative heat transfer (NFRHT). In this work, we investigated the ENZ characteristics of the NFRHT between two symmetric biaxial α-MoO slabs.

An ultra-broadband and wide-angle absorber based on a TiN metamaterial for solar harvesting.

The efficient absorption of solar spectrum radiation is the most critical step in solar thermal utilization. In this work, a near-perfect metamaterial solar absorber with broadband, wide angle, polarization insensitivity, and high-temperature resistance is proposed and investigated. The absorber takes advantage of the high melting point material, which consists of a TiN reflector, a SiO insulating layer, and a TiN ring array.

The optical properties of dumbbell-type nanorods for solar photothermal conversion.

Due to localized surface plasmon resonance (LSPR), plasmonic nanoparticles have exciting potential for improving solar photothermal conversion performance and have been extensively studied. However, in addition to enhanced solar absorption, scattering is also enhanced with the occurrence of LSPR, which is detrimental to the direct absorption of solar energy. The nanoparticles that can excite magnetic resonance can alleviate the above problem but have rarely been studied.

Metasurfaces Assisted Twisted α-MoO for Spinning Thermal Radiation.

Spinning thermal radiation has demonstrated applications in engineering, such as radiation detection and biosensing. In this paper, we propose a new spin thermal radiation emitter composed of the twisted bilayer α-MoO metasurface; in our study, it provided more degrees of freedom to control circular dichroism by artificially modifying the filling factor of the metasurface. In addition, circular dichroism was significantly enhanced by introducing a new degree of freedom (filling factor), with a value that could reach 0.

Spinning thermal radiation from twisted two different anisotropic materials.

Thermal radiation has applications in numerous fields, such as radiation cooling, thermal imaging, and thermal camouflage. Micro/nanostructures such as chiral metamaterials with polarization-dependent or symmetry-breaking properties can selectively emit circularly (spin) polarized polarization waves. In this paper, we propose and demonstrate the spinning thermal radiation from two twisted different anisotropic materials.

Optical axis-driven modulation of near-field radiative heat transfer between two calcite parallel structures.

Recently, the increasing research on the anisotropic optical axis (OA) has provided a novel way to control light. However, this method is rarely applied to modulate the near-field radiative heat transfer (NFRHT). In this work, we investigate the influences of the OA orientation of calcite on the NFRHT between two calcite parallel structures.