Owing to its relatively high efficiency, extended transmission range, and less exposure to radio frequency radiation, near-field resonant wireless power transfer (R-WPT) has been widely used in consumer electronics and bio-implants. For most applications, a well-regulated output voltage is required against the coupling and loading variations, and thus a regulation scheme should be employed in an R-WPT system. To achieve an optimal receiver (RX) or overall efficiency, together with a reduced cost overhead, several regulation schemes have been proposed in recent years, where the regulation can be implemented at either the RX or transmitter (TX) side, or both. These regulation schemes have been reviewed and comprehensively discussed in this paper. Hence, the main contribution of this paper is to provide a guideline for designing the regulation scheme in R-WPT systems. Moreover, potential new topologies of regulation are investigated here.

Optical camera communications (OCC) has been growing rapidly in recent years, which offers a flexible and low-cost way to achieve underwater wireless optical communication (UWOC). However, the existence of underwater bubbles and suspended impurities will greatly decrease the signal quality. In this paper, we propose a de-bubble algorithm and a sampling scheme based on binary fringes correction (BFC) to enhance the communication quality. The experimental results demonstrate that a robust transmission can be achieved in the harsh bubble environment by applying the proposed two algorithms.

Metasurfaces have emerged as a unique group of two-dimensional ultra-compact subwavelength devices for perfect wave absorption due to their exceptional capabilities of light modulation. Nonetheless, achieving high absorption, particularly with multi-band broadband scalability for specialized scenarios, remains a challenge. As an example, the presence of atmospheric windows, as dictated by special gas molecules in different infrared regions, highly demands such scalable modulation abilities for multi-band absorption and filtration. Herein, by leveraging the hybrid effect of Fabry–Perot resonance, magnetic dipole resonance and electric dipole resonance, we achieved multi-broadband absorptivity in three prominent infrared atmospheric windows concurrently, with an average absorptivity of 87.6% in the short-wave infrared region (1.4–1.7 μm), 92.7% in the mid-wave infrared region (3.2–5 μm) and 92.4% in the long-wave infrared region (8–13 μm), respectively. The well-confirmed absorption spectra along with its adaptation to varied incident angles and polarization angles of radiations reveal great potential for fields like infrared imaging, photodetection and communication.

We fabricated high-performance InSnZnO (ITZO) thin-film transistors (TFTs) with self-assembled monolayers (SAMs)/Al ₂ O ₃ double passivation layers (PVLs). The presented SAMs/Al ₂ O ₃ double passivation leads to high-performance ITZO TFTs with a steep subthreshold slope (~85 mV/dec), a low threshold voltage (~0.9 V), high mobility (~19.8 cm ² V ^-1 s ^-1 ), and high on-off current ratio (~8.7 × 10 ⁹ ). Moreover, compared to devices with Al ₂ O ₃ PVL, ITZO TFTs with SAMs/Al ₂ O ₃ double PVLs show better stability in ambient air with a relative humidity of 60% under positive bias stress (PBS) and negative bias stress (NBS). This enhanced stability is attributed to the presence of a high-quality SAM/Al ₂ O ₃ dual PVL, which not only inhibits Vo-related trap sites and reduces overall trap density, but also protects the back-channel from environmental influences.

Visible light positioning (VLP) has been studied widely due to its high accuracy and low cost in the field of location-based services (LBS). However, many existing VLP systems have the requirements that the receiver should be placed horizontally and more than three LED lamps should be used, which are difficult to meet in practical scenarios. Therefore, it is necessary to develop a novel VLP algorithm for tilted conditions. An effective and simple VLP system while the receiver is tilted based on double-LED lamps is proposed in this paper. The vertical position can be determined by combining the information from angle sensors with geometric information. Through analyzing the imaging characteristics of the tilted state, we can utilize the relationship of similarity to calculate the location of the mobile receiver. Experimental results show that the positioning accuracy of our proposed algorithm can reach 5.48 cm.

The unprecedented capability of metasurfaces in pixel-wise-level accurate light manipulation has enabled the realization of polarization-multiplexed metasurface holograms in a single or multiple channel. However, most metasurfaces are static and unable to realize active or tunable wave control in many scenarios. We introduce an erasable functionality for multi-channel metasurface holograms based on active phase tuning, which is realized using the nonvolatile chalcogenide phase change alloy of GeSbSeTe (GSST). Upon the incidence of linearly or circularly polarized waves, polarization-dependent holograms constructed using amorphous GSST (a-GSST) elliptical pillars are achieved because of the complete phase control. The a-GSST holograms feature a subwavelength spatial resolution for all elliptical pillars, with local transmittances ranging from 66% to 90%. Benefiting from the amorphous-to-crystalline phase transition of GSST, the hologram functionality can be completely erased because the crystallized pillars cannot provide the effective propagation modes required by the anisotropic phase modulations in the operating wavelength range. The unique properties of the proposed polarization-multiplexed holograms with erasable functionality offer more degrees of freedom and have potential applications in many fields, such as anti-counterfeiting, encryption, and holographic sources.