Reflective Layer Research Articles

Transmission Removal from a Single Glass Scene and Its Application in Photographer Identification

In daily life, when taking photos of scenes containing glass, the images of the dominant transmission layer and the weak reflection layer are often blended, which are difficult to be uncoupled. Meanwhile, because the reflection layer contains sufficient important information about the surrounding scene and the photographer, the problem of recovering the weak reflection layer from the mixture image is of importance in surveillance investigations. However, most of the current studies mainly focus on extracting the transmission layer while often ignoring the merit of the reflection layer. To fill that gap, in this paper, we propose a network framework that aims to accomplish two tasks: (1) for general scenes, we attempt to recover reflection layer images that are as close as possible to the ground truth ones, and (2) for scenes containing portraits, we recover the basic contour information of the reflection layer while improving the defects of dim portraits in the reflection layer. Through analyzing the performance exhibited by different levels of feature maps, we present the first transmission removal network based on an image-to-image translation architecture incorporating residual structures. The quality of generated reflection layer images is improved via tailored content and style constraints. We also use the patch generative adversarial network to increase the discriminator’s ability to perceive the reflection components in the generated images. Meanwhile, the related information such as edge and color distribution of transmission layer in the mixture image is used to assist the overall reflection layer recovery. In the large-scale experiments, our proposed model outperforms reflection removal-based SOTAs by more than 5.356 dB in PSNR, 0.116 in SSIM, and 0.057 in LPIPS.

Many Facets of Photonic Crystals: From Optics and Sensors to Energy Storage and Photocatalysis

AbstractThe ability to selectively redirect specific wavelengths of light has attracted a lot attention for photonic crystal materials. Presently, there is a wealth of research relating to the fabrication and application of photonic crystal materials. There are a number of structures that fall into the category of a photonic crystal; 1D, 2D, and 3D ordered structures can qualify as a photonic crystal, provided there exists ordered repeating lattices of dielectric material with a sufficient refractive index contrast. The optical responses of these structures, namely the associated photonic bandgap or stopband, are of particular interest for any application involving light. The sensitivity of the photonic bandgap to changes in lattice size or refractive index composition creates the possibility for accurate optical sensors. Optical phenomena involving reduced group velocity at wavelengths on the edge of the photonic bandgap are commonly exploited for photocatalytic applications. The inherent reflectivity of the photonic bandgap has created applications in optical waveguides or as solar cell reflector layers. There are countless examples of research attempting to exploit these facets of photonic crystal behavior for improved material design. Here, the role of photonic crystals is reviewed across a wide variety of disciplines; cataloging the ways in which these structures have enhanced specific applications. Particular emphasis is placed on providing an understanding of the specific function of the tunable optical response in photonic crystals in relation to their application.

Statistical Analysis for Parameters of Specularly Reflective Layers in High-Level Clouds over Western Siberia Based on MODIS Data

Statistical Analysis for Parameters of Specularly Reflective Layers in High-Level Clouds over Western Siberia Based on MODIS Data

Enhancing radiative cooling performance for bifacial photovoltaic module using two kinds of polycarbonate films

Radiative cooling, as a cooling method that does not consume any energy during operation, has become a hot topic in recent years. Unlike passive daytime radiative cooling in buildings, radiative coolers used in photovoltaic modules must also have high light transmittance, which undoubtedly makes relevant research more difficult. Currently, bifacial photovoltaic modules are widely available on the market, if traditional cooling methods are employed in the back of them, including passive cooling such as heat sink and active cooling such as air cooling and water cooling, it will block the rear irradiance into the module. Hence, radiative cooling is an excellent solution. In this paper, polycarbonate (PC) film and one composed with a high reflective layer are proposed. The former has high emissivity in the atmospheric window and the latter has high reflectivity in the near-infrared band. Both achieve a good cooling effect without affecting the normal operation of the module. We also prepared the reflective film on PC by magnetron sputtering, and its optical characteristics were also measured and compared with simulation results. We innovatively use PC material and combine the reflective film with quite simple structure. Compared with other research results, they are simpler and stabler film structures and have the advantages of low cost, easy installation, good cooling effect, and can be directly pasted on the surface of the photovoltaic module. It turns out that the cooling effect can reach 6.02°C with R-PC film and photoelectric conversion efficiency can be improved by 0.27% with PC film when hc = 20 W · m − 2 · K − 1 and Ta = 27 ° C. Given its excellent performance, they have a broad application prospect in the daytime passive radiative cooling of bifacial photovoltaic modules.

Development, testing, and evaluation of the daylighting, thermal, and energy-saving performance of semitransparent radiative cooling glass in cooling-dominated regions

Glass-made building envelopes play an essential role in buildings’ thermal/daylighting environment and energy behavior. To enhance its overall energy efficiency in cooling-dominated regions, a double-layer film that combines the concepts of selective solar utilization (SSU) and radiative cooling (RC) is proposed to form the semitransparent energy-saving glass (SESG). The SSU film (∼0.1 mm) is a multilayer optical film that contains polyethylene terephthalate (PET) and thin reflective metal layer. The RC film (∼0.1 mm) consists of a PET layer and an adhesion layer. To evaluate the daylighting, thermal, and energy-saving performance of the SESG on buildings, comparative field tests using reduced-size model boxes and whole-building energy simulation analysis on a larger-scale office building are conducted. Compared with the normal clear glass, the developed SESG decreases the indoor air temperature of the modeled box by maximum values of 19.1℃ and 17.8℃ while reducing the daylighting level by 68 % to support a more comfortable thermal/daylighting environment. In addition, a single-story office building modeling using EnergyPlus was developed to evaluate the energy-saving and daylighting performance of the SESG in two different cooling-dominated cities, Male (Maldives) and Hong Kong (China) considering different glazing ratios. Compared with normal clear glass which will add amounts of extra cooling load and cause serious glare problems due to its high transmittance to visible light and near-infrared solar radiation, the annual cooling energy savings of the SESG reach 15 %—60 % in two selected cities under different glazing ratios. By considering both energy-saving potential and daylighting quality, the simulation results show that in Male, within the glazing ratios of 0.4 to 0.6, the UDI (Useful Daylighting Illuminance) values and energy-saving potential both reach the highest value of 0.5–0.6 and ∼ 55 %. In Hong Kong, the UDI values and energy-saving potential both reach the highest value of 0.4–0.5 and ∼ 57 % when the glazing ratio ranges between 0.5 and 0.9. The experimental and simulation results validate that combining selective solar utilization and radiative cooling for the glass envelopes is able to seek a more efficient balance between the energy behaviors and daylighting environment for buildings in cooling-dominated regions.

Tunable narrowband excitonic Optical Tamm states enabled by a metal-free all-organic structure

Abstract Optical Tamm states (OTS) are confined optical modes that can occur at the interface between two highly reflective structures. However, due to the strong reflectance required, their implementation with highly processable and metal-free flexible materials has proven challenging. Herein, we develop the first structure supporting OTS based only on organic polymeric materials, demonstrating a photonic platform based on non-critical, widely available and easily processable materials. The structures fabricated present large areas and consist of a narrowband multi-layered polymeric distributed Bragg reflector (DBR) followed by a thin film of J-aggregate molecular excitonic material that can act as a highly reflective surface within a narrowband range. We take advantage of the narrowband spectral response of the DBR and of the reflective molecular layer to tune the OTS band by varying the periodicity of the multilayer, opening the door for the fabrication of OTS structures based on lightweight integrable excitonic devices with cost-effective procedures.

Semidecoupled decomposition-based fractional-order variational model for low-light enhancement

Low-light enhancement is an important technique for improving image quality. This is because low-light enhancement is expected to improve image visibility while maintaining visual naturalness of the image. In recent years, many methods have been researched to enhance low-light images, including histogram-based, fusion-based, and learning-based methods. The most representative and widely used low-light image enhancement method is the so-called Retinex-based method. However, they tend to have many limitations. The limitations of the Retinex-based method are as follows. (1) Due to strong imaging noise or less-effective image decomposition, this results in a large number of artifacts in the enhanced results. (2) Although the first problem can be partially solved by exploring prior information, it often complicates the optimization process. (3) Small-magnitude details are often lost in enhanced results. To overcome these drawbacks, we propose a model called the fractional-order Retinex model. At the same time, Retinex images are decomposed in an effective semidecoupled way. More concretely, the illumination layer T is gradually estimated only with the observed image S based on the proposed variation model, whereas the reflectance layer R is jointly estimated by the intermediate T and S. Experimental results demonstrate the effectiveness of our method.

Polarization Selective Partial Reflective Decoupling Layers for Mutual Coupling Reduction of Two Closely Spaced Dual-Polarized Antennas

In this communication, two polarization selective partial reflective decoupling layers (PRDLs) are utilized to mitigate at least two kinds of mutual couplings between two closely spaced dual-polarized dipole antennas. The PRDL is a large-scale model of an actual dielectric board, obtained by arranging a large number of identical conducting obstacles in a regular two-dimensional pattern. The two PRDLs are designed at proper distances from the antenna aperture with well-engineered dielectric constants for two preset polarizations. Each layer is selective to only one polarization by appropriately designing the dimension of the unit cells. Consequently, the two dominant couplings between the two dual-polarized antennas are reduced significantly. The measured isolation between all ports of the two antennas are increased to more than 21 dB, while their reflection coefficients can still maintain in satisfactory status. The radiation patterns, total efficiencies, and envelop correlation coefficients of the proposed antenna, as well as its counterpart without any decoupling measures, are also obtained through measurement, showing significant and reasonable improvements, which further indicates that it has great potential to be extended and applied to 5G MIMO arrays in both base stations and wireless routers.

A Novel Dual-Band Shared-Aperture Antenna Based on Folded Reflectarray and Fabry–Perot Cavity

This communication proposes a novel dual-band shared-aperture antenna hybridizing Fabry–Perot cavity antenna (FPCA) and folded reflectarray (FRA), which operates at both sub-6 GHz and millimeter-wave bands with a large frequency ratio of 1:4.6. This antenna is composed of two substrates, with metasurface printed on the upper substrate and reflector layer printed on the lower one. The metasurface works as partially reflective surface (PRS) of FPCA at the sub-6 GHz band while acts as polarization grid of FRA at the millimeter-waveband. Thus, the FPCA and the FRA are able to share the same aperture with high aperture reuse efficiency. A composite feed structure combining waveguide with microstrip patch antenna is used to feed at two bands, implementing shared-aperture feed. This antenna achieves high gains at two bands without complicated feeding networks. A prototype operating at 5.4 and 25 GHz bands is designed, fabricated, and measured to verify the idea.

Safety Analysis of Landslide in Pipeline Area through Field Monitoring

Abstract Although the triggering of landslides is closely related to environmental factors, several other factors also contribute toward these landslides. Simple data observation of a single factor, such as displacement or rainfall, cannot clearly explain the relationship between landslide hazards and environmental factors in oil and gas pipeline areas. Based on the systematic summary of domestic and foreign pipeline landslide hazard monitoring and data analysis technologies, this study selects the high-risk section of an oil and gas transmission pipeline area as the research object and analyzes the characteristics and distribution of geological hazards along the pipeline. Studies have shown that the overlying soil of the landslide body, with an uneven thickness of approximately 3 m, consists of two reflection layers reflecting the electromagnetic signals of radar. Between November 2019 and November 2020, the maximum monthly cumulative rainfall occurred in June 2020, which was 419.7 mm, in addition to a cumulative rainfall of up to 108 mm that occurred in a single day. During this time, the soil moisture content at a depth of 1.5 m is the most sensitive factor in response to rainfall events. The water content of the soil fluctuates with depth due to diffusion and seepage. After a heavy rainfall, the leading edge of the landslide exhibited displacement and dragged the trailing edge along with it. The pipeline strain also fluctuated significantly with the displacement. The effect on the pipe changed from compressive strain to tensile strain and back to compressive strain, indicating that a landslide due to rainfall causes concentrated stress and deformation of the pipeline, thereby affecting its safety.

Semantic Guided Single Image Reflection Removal

Reflection is common when we see through a glass window, which not only is a visual disturbance but also influences the performance of computer vision algorithms. Removing the reflection from a single image, however, is highly ill-posed since the color at each pixel needs to be separated into two values belonging to the clear background and the reflection, respectively. To solve this, existing methods use additional priors such as reflection layer smoothness, double reflection effect, and color consistency to distinguish the two layers. However, these low-level priors may not be consistently valid in real cases. In this paper, inspired by the fact that human beings can separate the two layers easily by recognizing the objects and understanding the scene, we propose to use the object semantic cue, which is high-level information, as the guidance to help reflection removal. Based on the data analysis, we develop a multi-task end-to-end deep learning method with a semantic guidance component, to solve reflection removal and semantic segmentation jointly. Extensive experiments on different datasets show significant performance gain when using high-level object-oriented information. We also demonstrate the application of our method to other computer vision tasks.

1-D Magnetic photonic crystal as intermediate reflective layer in tandem solar cells

The analysis of the optical properties of a 1-D binary magnetic photonic crystal (MPC) made up of Cu-doped YIG, a metal-doped magnetic composite material as one layer, and μc-SiOx:H as another layer is carried out. The refractive index of the Cu-YIG nanocomposite system is calculated using the Maxwell-Garnett equation. The transmission spectra of 1-D MPC is studied using the Transfer Matrix Method. The proposed 1-D MPC is designed in such a way that it is suitable to act as an intermediate reflective layer (IRL) in thin-film silicon tandem solar cells. The reference Bragg wavelength (λB) is set at 500 ​nm. The effect of copper doping in the magnetic photonic crystal on the photonic bandgap is studied. By varying the number of periods and the percentage of copper doping, the changes in the photonic bandgap are analysed. It is found that the photonic bandgap increases with the number of periods of the MPC and the percentage of copper doping, which tends to enhance the light trapping in tandem solar cells.

Double layered design for electromagnetic interference shielding with ultra-low reflection features: PDMS including carbon fibre on top and graphene on bottom

Electromagnetic interference (EMI) shielding materials with low reflection features have become necessary for a new generation of electronic devices to reduce secondary electromagnetic pollution. Here, a novel strategy is adopted to provide flexible polydimethylsiloxane (PDMS) composite films with ultra-low reflection EMI shielding performance by constructing a double-layer structure with uniformly dispersed carbon fibres (CFs) in the upper layer as an impedance-matching absorption layer and continuous graphene fibres (GFs) located at the bottom layer as a conductive reflection layer. The resulting specific structure significantly reduces the reflectivity of the composite film at extremely low carbon conductive fillers (0.01 wt% CFs and 1.00 wt% GFs) through the process of “absorption-reflection-reabsorption” when incident electromagnetic waves (EMWs) pass through the composite film: the total shielding effectiveness (SETotal) achieves 34.4 dB at 18.0 GHz, while the shielding effectiveness of reflection (SER) is only 0.1 dB, and reflection coefficient (R) is as low as 0.018. This phenomenon indicates that 1.8% of the incident EMWs are reflected in the propagation process when 99.96% are attenuated. In addition, the shielding mechanism of the double-layer EMI shielding composite films with low reflection features is studied in depth. This study provides a reliable idea for designing flexible EMI shielding materials with ultra-low reflection to alleviate secondary electromagnetic radiation pollution.

Adsorption of oleic acid on magnetite facets

The microscopic understanding of the atomic structure and interaction at carboxylic acid/oxide interfaces is an important step towards tailoring the mechanical properties of nanocomposite materials assembled from metal oxide nanoparticles functionalized by organic molecules. We have studied the adsorption of oleic acid (C17H33COOH) on the most prominent magnetite (001) and (111) crystal facets at room temperature using low energy electron diffraction, surface X-ray diffraction and infrared vibrational spectroscopy complemented with molecular dynamics simulations used to infer specific hydrogen bonding motifs between oleic acid and oleate. Our experimental and theoretical results give evidence that oleic acid adsorbs dissociatively on both facets at lower coverages. At higher coverages, the more pronounced molecular adsorption causes hydrogen bond formation between the carboxylic groups, leading to a more upright orientation of the molecules on the (111) facet in conjunction with the formation of a denser layer, as compared to the (001) facet. This is evidenced by the C=O double bond infrared line shape, in depth molecular dynamics bond angle orientation and hydrogen bond analysis, as well as X-ray reflectivity layer electron density profile determination. Such a higher density can explain the higher mechanical strength of nanocomposite materials based on magnetite nanoparticles with larger (111) facets.

Smart current collector for high-energy-density and high-contrast electrochromic supercapacitors toward intelligent and wearable power application

Integrating electrochromism and energy storage into supercapacitor is highly desirable for the development of intelligent and wearable sustainable power system and electronics. However, simultaneous realization of high energy storage and high electrochromic performances remains a major challenge in electrochromic energy storage due to their inherent contradiction in transmissive-type device designs. Herein we demonstrate a smart current collector (SCC) strategy for simultaneously realizing a high energy density and a high electrochromic contrast in supercapacitors. SCC is designed by sandwiching an electrochromic polypyrrole layer between transparent substrate and porous Ag reflective layer, which possesses high reflective-type electrochromic performances, excellent conductivity and enables a high-mass loading of active energy storage material without sacrificing good ion access to electrochromic layer. While achieving high electrochromic-contrast performances at a high mass loading of active material, the electrochromic supercapacitor based on SCC can deliver a high energy density of 112.2 μWh cm−2, significantly outperforming the reported electrochromic supercapacitors to date. Moreover, SCC design perfectly suits for wearable power supply application as it is hardly affected by the wearable-background lightness. The delicate design of current collector in this work provides a new technology for developing high-performance intelligent wearable electrochemical energy storage devices toward real applications.

Polarized reflection removal with difference feature attention guidance.

Reflection removal is of great significance for high-level computer vision tasks. Most existing methods separate reflections relying heavily on the quality of intermediate prediction or under certain special constraints. However, these methods ignore the inherent correlation between the background and reflection, which may lead to unsatisfactory results with undesired artifacts. Polarized images contain unique optical characteristics that can facilitate reflection removal. In this paper, we present, to the best of our knowledge, a novel two-stage polarized image reflection removal network with difference feature attention guidance. Specifically, our model takes multi-channel polarized images and Stokes parameters as input and utilizes the optical characteristics of reflected and transmitted light to alleviate the ill-posed nature. It adopts a simple yet effective two-stage structure that first predicts the reflection layer and then refines the transmission layer capitalizing on the special relationship between reflection and transmission light. The difference feature attention guidance module (DFAG) is elaborated to diminish the dependence on intermediate consequences and better suppress reflection. It mitigates the reflection components from the observation and generates the supplement and enhancement to the transmission features. Extensive experiments on the real-world polarized dataset demonstrate the superiority of our method in comparison to the state-of-the-art methods.

Shallow gas and gas hydrate accumulations influenced by magmatic complexes in the Pearl River Mouth Basin, South China Sea

We analyse occurrences of gas hydrates and free gases above a 1200 km2 complex of igneous volcanoes and sills using newly acquired three-dimensional (3D) seismic data in the Pearl River Mouth Basin of the South China Sea. In strata above volcano summits, we recognize three enhanced reflection layers at different stratigraphic levels, including discontinuous Bottom Simulating Reflectors (BSRs) and pluming BSRs. We also show that the lateral tips of eight sills, which at times appear to terminate against supra-sill faults, underlie gas chimneys linked to gas hydrate and free gas in shallower strata. These supra-sill faults and gas chimneys, as well as supra-volcano faults, provided pathways for upward fluid (gas) migration from deep sources. Given the spatial relationship between volcanoes, sills, free gas, and gas hydrates, we suggest that the igneous structures focused fluid migration into overlying faults and gas chimneys. We also explore whether higher geothermal gradient at the summits of the volcanoes caused the base of gas hydrate stability zone to be shallower, forming a pluming BSR. Our study highlights how volcanic systems can influence the formation and distribution of later gas hydrate and free gas.

Development and Evaluation of Copper Based Transparent Heat Reflectors Obtained by Magnetron Sputtering.

Within the next few years climate change is likely to become a major concern for mankind. In addition, the current electronic components shortage crisis has led to an urgent need for alternative solutions in the main industry sectors (the raw materials, manufacturing, and construction industries). The current trends of research are focused on developing smart materials with functional properties, using abundant raw materials. The energy saving efforts are sustained in the glazing industries by several approaches based on dielectric-metal-dielectric multilayer structures. The use of silver to achieve a high reflectivity in near-infrared spectral range has been proposed and is already adopted as a commercially available solution. This work is focused on developing a transparent heat reflector (THR) with prefigured optical properties, using copper as a reflective layer, a material that is more abundant and cheaper than silver. The conductive copper layers obtained by the High Power Impulse Magnetron Sputtering (HiPIMS) method were interposed between two silicon nitride layers deposited by the Radio-Frequency Magnetron Sputtering (RFMS) technique. The structural, optical, and elemental composition of monolayers was investigated, qualifying each individual material for use in the multilayer structure. The time stability of films deposited on microscope glass substrates was also investigated, as an important criterion for the selection of monolayers. The obtained results revealed that the SiNx/Cu/SiNx with the Cu layer deposited by using a negative substrate bias of −100 V showed the most stable behavior over time. Optical modeling was performed to design a THR multilayer structure, which was successfully obtained experimentally. A maximum optical transparency as high as 75% in the visible range and a reflectivity of ~ 85% in near infrared spectral interval was confirmed for the experimentally obtained multilayer structures.

(Invited) Achieving High-Power Single-Mode Operation in Vertical-Cavity Surface-Emitting Lasers Via Scalable, Higher-Order Mode Suppression Techniques

Achieving high-power single-mode operation in Vertical-Cavity Surface-Emitting Lasers (VCSELs) has received renewed interest because of applications that span facial recognition and 3D imaging in mobile telephones, Light Detection and Ranging (LiDAR) for autonomous vehicles, and Pulse Amplitude Modulation (PAM-4) for high-speed (>100 Gbps) data transmission within data centers. A key challenge with oxide-confined VCSELs is that the strong refractive index contrast between the oxidized ~AlAs aperture and surrounding AlGaAs layers combined with the oxide aperture size create a photonic cavity that fundamentally supports multiple transverse modes. When the size of the aperture is reduced to create a single-mode cavity, the output power is limited by the electrically pumped gain region within the aperture. There is thus a fundamental trade-off between size and power which manifests itself in a limited capability to simultaneously achieve high power and single mode operation. Various methods have been employed by groups working on VCSELs to overcome this limitation. Neglecting external cavity methods which are fundamentally not scalable, the most promising results have been achieved by groups using etched surface relief where a pattern is etched in the top layer or layers to change the standing wave pattern in the cavity and reduce modal gain by lowering the magnitude of the electric field in regions overlapping with the quantum wells, which provide laser gain. A downside of this approach is that material is removed, impacting the uniformity of current injection across the area of the device. A key question of interest is therefore how to achieve mode suppression in large area devices in a way that does not impact current injection. In this presentation, novel methods for mode control that rely on spatial variation of modal gain across the area of the VCSEL aperture will be discussed, and results on high-power single-mode operations of VCSELs will be presented. Two distinct mode control methods will be reviewed. The first method of mode control uses deposited optical coatings on the top surface of the VCSEL to spatially modify the electric field standing wave in the quantum well heterostructure region. Through patterning the coating in either a pillar or anulus, specific modes can be suppressed by selectively changing the gain available for those modes. These filters have been made using both SiO2/TiO2 stacks and alternatively a single layer of silicon. The capability to pattern these layers in a wafer-scale process makes this method attractive for volume manufacturing. The second method of mode control utilizes impurity-induced layer disordering via patterned diffusion of Zn to selectively intermix Distributed Bragg Reflector (DBR) layers, thereby creating a top laser mirror whose reflectivity varies spatially across the aperture. Designing the diffused region to maximize overlap with high-order modes while minimizing overlap with the fundamental mode provides mode suppression and enhanced single-mode power. An added benefit of this approach is a reduction in resistance through the device top DBR layers brought about by the higher p-doping level in the Zn-diffused regions, minimizing Ohmic losses and heat generation. Through the use of strain control in the diffusion mask, diffusion front shape is also shown to be controllable in a way that can be used to minimize the impact of the diffused region on fundamental mode reflectivity. Tensile and compressive strain of diffusion masks are shown to have differing effects on vertical (into the device) versus lateral (across the area of the device under the mask) diffusion, allowing more precise spatial control of reflectivity. Using these methods, single-mode output powers in excess of 10 mW have been demonstrated, with side-mode suppression ratios in excess of 30 dB. These results will be discussed, as well as further work to enhance VCSEL performance. Figure 1

Refractory Plasmonic Hafnium Nitride and Zirconium Nitride Thin Films as Alternatives to Silver for Solar Mirror Applications.

Harnessing solar energy by employing concentrated solar power (CSP) systems requires materials with high electrical conductivity and optical reflectivity. Silver, with its excellent optical reflectance, is traditionally used as a reflective layer in solar mirrors for CSP technologies. However, silver is soft and expensive, quickly tarnishes, and requires a protective layer of glass for practical applications. Moreover, supply-side constraints and high-temperature instability of silver have led to the search for alternative materials that exhibit high solar and infrared reflectance. Transition metal nitrides, such as titanium nitride, have emerged as alternative plasmonic materials to gold starting from a spectral range of ∼500 nm. However, to achieve high solar reflection (∼320-2500 nm), materials with epsilon-near-zero starting from the near-ultraviolet (UV) spectral region are required. Here, we show the development of refractory epitaxial hafnium nitride (HfN) and zirconium nitride (ZrN) thin films as excellent mirrors with a solar reflectivity of ∼90.3% and an infrared reflectivity of ∼95%. Low-loss and high-quality epsilon-near-zero resonance at near-UV (∼340-380 nm) spectral regions are achieved in HfN and ZrN by carefully controlling the stoichiometry, leading to a sharp increase in the reflection edge that is on par with silver. Temperature-dependent reflectivity and dielectric constants are further measured to demonstrate their high-temperature suitability. The development of refractory epitaxial HfN and ZrN thin films with high solar and infrared reflectance makes them excellent alternative plasmonic materials to silver and would pave their applications in CSP, daytime radiative cooling, and others.