Spectral Emissivity Research Articles

Environmental conical nozzle levitator equipped with dual wavelength lasers

AbstractThe environmental conical nozzle levitator (E‐CNL) with dual‐wavelength lasers is an extreme environment materials characterization system that was designed to investigate ultra‐high‐temperature materials: refractory metals, oxides, carbides, and borides above 3000 K in a controlled atmosphere. This article details the characterizations using this system to establish its high‐temperature capabilities and to outline ongoing work on materials under extreme conditions. The system has been used to measure the melting point of several oxide materials (TiO2, Tm = 2091 ± 3 K; Al2O3, Tm = 2310 3 K; ZrO2, Tm = 2984 31 K; and HfO2, Tm = 3199 ± 45 K) and several air‐sensitive refractory metals (Ni, Tm = 1740 K; Ti, Tm = 1983 K; Nb, Tm = 2701 K; and Ta, Tm = 3368 K—note: mean ± standard deviation) during levitation which matched literature values within 0.17–2.43 % demonstrating high accuracy and precision. This containerless measurement approach is critical for probing properties without container‐derived contamination, and dual‐wavelength laser heating is essential to heat both relatively poor electrical conductors (some refractory metals and carbides) and insulators (oxides). The highest temperature achieved utilizing both lasers in these experiments was ∼4250 ± 34 K on a 76.6 mg, molten HfO2 sample using a normal spectral emissivity of 0.91. Stable levitation was demonstrated on spherical samples (yttria‐stabilized zirconia) while adjusting levitation gas composition from pure oxygen to pure argon, verifying atmospheric control up to 3173 K on solid or molten samples. These successes demonstrate the viability of in situ high‐temperature environmentally controlled studies potentially up to 4000 K on all classes of ultra‐high‐temperature materials in one system. These measurements highlight the E‐CNL system will be essential for the development of next‐generation ultra‐high‐temperature materials for hypersonic platforms, nuclear fission and fusion, and space exploration.

Characterization of directional and anisotropic scattering dependency of emissivity for fibrous heat shields under non-isothermal conditions

The spectral and directional dependence of emissivity along with radiative emissions of scattering media has been characterized as functions of the optical thickness, scattering albedo, and anisotropic scattering phase function. Emissivity is found to be a strong function of the scattering albedo and the anisotropic scattering phase function of the medium, and a generalized relation between spectral emissivity and scattering behavior for thick optical media is developed through the use of Bézier curves. A comparison of the newly developed relation with the spectral emissivities of silica- and carbon-based fibrous media demonstrated excellent agreement, with a root mean square error of 0.19%. The characterization of directional emissivity through scattering media indicates that directional emissivity is higher than hemispherical emissivity in directions normal to the surface, but drops at polar angles greater than 50° because of increased reflection. A novel model is also developed to capture emissions from a medium with a non-uniform temperature distribution using the same emissivities derived under isothermal conditions, but with an effective blackbody temperature, which differs from the surface temperature of the medium. The new emission model exhibited excellent agreement compared to the true emissions under various conditions, with a root mean square error of 1.27%. This new approach offers a practical computationally tractable solution for the radiation energy balance at surfaces that can be used in current state-of-the-art computational fluid dynamics and thermal response simulations.

Precision black body model at a temperature of 200–450 K:metrological ensurance for optical-electronic equipment for remote sensing of the Earth in the infrared range of the spectrum

The issues of radiometric calibration of optical-electronic equipment for remote sensing of the Earth in a wide range of spectral radiance have been studied. An alternative method for transmitting a spectral radiance unit from a reference source at the phase transition temperature of pure metals to optical-electronic equipment for remote sensing of the Earth in the infrared wavelength range above 2.5 μm is presented. The method is based on the stepwise transfer of a spectral radiance unit from a reference source through a precision model of a black body with a high level of emissivity and a wide temperature range identical to the temperature range of a wide-aperture black body model with a range of spectral radiance required for calibrating optical-electronic equipment for remote sensing of the Earth. A precision black body model PMBB-60m with an output aperture with a diameter of 30 mm was developed, studied and calibrated in the temperature range of 200–450 K. The calculated value of the effective emissivity of PMBB-60m with coating of the cavity by Aeroglaze Z306 paint is 0.9997. The composition and design of PMBB-60m are described. PMBB-60m can operate both in vacuum conditions and in conditions of inert gas or atmospheric pressure. The metrological characteristics of PMBB-60m , obtained by transferring a temperature unit from the State Standard of the zero digit of a temperature unit in the range from 0 to 3000 °C using a comparator, based on a precision pyrometer TRT II (Heitronics Infrarot Messtechnik GmbH, Germany) are presented. The correction to the PMBB-60m temperature readings in the temperature range of 223.15–450.15 K did not exceed 39 mK according to the results of calibration in the temperature range of 223.15–450.15 K. The results of calculating the expanded uncertainty in the temperature range of 223.15–450.15 K did not exceed 1 K. The values of instability of temperature maintenance PMBB-60m, measured in steps of 10 s for 15 minutes, did not exceed 15 mK in the considered temperature range. The results of calculation of the spectral effective emissivity of PMBB-60m, carried out using the STEEP3 program, are presented.

Thickness and Roughness Effect of Pr2NiO4+δ Coating on the Normal Spectral Emittance

Thickness and Roughness Effect of Pr2NiO4+δ Coating on the Normal Spectral Emittance

A straightforward spectral emissivity estimating method based on constructing random rough surfaces

Spectral emissivity is an essential and sensitive parameter to characterize the radiative capacity of the solid surface in scientific and engineering applications, which would be non-negligibly affected by surface morphology. However, there is a lack of assessment of the effect of roughness on emissivity and a straightforward method for estimating the emissivity of rough surfaces. This paper established an estimating method based on constructing random rough surfaces to predict rough surface (Geometric region) emissivity for metal solids. Based on this method, the emissivity of ideal gray and non-gray body surfaces was calculated and analyzed. The calculated and measured spectral emissivities of GH3044, K465, DD6, and TC4 alloys with different roughness were compared. The results show that the emissivity increases with the roughness degree, and the enhancement effect weakens with the increase of roughness or emissivity due to the existing limit (emissivity ε = 1.0). At the same time, the roughness would not change the overall spectral distribution characteristics but may attenuate the local features of the spectral emissivity. The estimated results are in good agreement with the experimental data for the above alloys’ rough surfaces. This study provides a new reliable approach to obtaining the spectral emissivity of rough surfaces. This approach is especially beneficial for measuring objects in extreme environments where emissivity is difficult to obtain. Meanwhile, this study promotes an understanding of surface morphology’s effect mechanism on emissivity.

Improved oxidation resistance and infrared emissivity of tantalum disilicide particles with sol-gel derived SiO2 coatings

As an important high-temperature structural material, tantalum disilicide (TaSi2) suffers from performance degradation associated with high temperature oxidation due to the poor oxygen diffusion barring effect of the mixed Ta2O5/SiO2 oxidation scale. In this work, silica coating was prepared on the surface of TaSi2 powder by a sol-gel method. The oxidation resistance was studied by thermogravimetric tests in non-isothermal oxidation and isothermal oxidation, as well as by oxidation treatment in a tube furnace at temperatures ranging from 800 °C to 1400 °C. The spectral emissivity of raw TaSi2, coated TaSi2 and the oxidized ones was compared and analyzed. The amorphous SiO2 coating is composed of numerous nanoparticles and covers most of the surface of TaSi2 particles. The oxidation weight gain of coated TaSi2 during heating from RT to 1200 °C and 1400 °C decreases from 29.8% and 30.9–3.0% and 8.6%, respectively. And the oxidation is controlled by diffusion in the overall process. The coated TaSi2 combines the advantageous radiation property of TaSi2 core and SiO2 coating. Compared with that of raw TaSi2, the emissivity of coated TaSi2 at the wavelength range of 200–2500 nm and 2.5–25 µm has increased by 7.5% and 13.2%, respectively, and the property did not deteriorate after oxidation at 1200 °C, suggesting that the coated TaSi2 is an excellent emitting agent during the entire service life.

ALMA Observations of the DART Impact: Characterizing the Ejecta at Submillimeter Wavelengths

We report observations of the Didymos–Dimorphos binary asteroid system using the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Compact Array (ACA) in support of the Double Asteroid Redirection Test mission. Our observations on UT 2022 September 15 provided a preimpact baseline and the first measure of Didymos–Dimorphos’s spectral emissivity at λ = 0.87 mm, which was consistent with the handful of siliceous and carbonaceous asteroids measured at millimeter wavelengths. Our postimpact observations were conducted using four consecutive executions each of ALMA and the ACA spanning from T+3.52 to T+8.60 hr, sampling thermal emission from the asteroids and the impact ejecta. We scaled our preimpact baseline measurement and subtracted it from the postimpact observations to isolate the flux density of millimeter-sized grains in the ejecta. Ejecta dust masses were calculated for a range of materials that may be representative of Dimorphos’s S-type asteroid material. The average ejecta mass over our observations is consistent with 1.3–6.4 × 107 kg, with the lower and higher values calculated for amorphous and crystalline silicates, respectively. Owing to the likely crystalline nature of S-type asteroid material, the higher value is favored. These ejecta masses represent 0.3%–1.5% of Dimorphos’s total mass and are in agreement with lower limits on the ejecta mass based on measurements at optical wavelengths. Our results provide the most sensitive measure of millimeter-sized material in the ejecta and demonstrate the power of ALMA for providing supporting observations to spaceflight missions.

Construction and experimental verification of optimal expansion wavelength (OEW) inertia criterion based on three-channel wide-spectrum temperature measurement technology

The optimal expansion wavelength (OEW) is a specific parameter that achieves the best approximation effect of the Taylor series on the temperature measurement integral equation. In the approximation of temperature measurement equations with different spectral emissivity, the OEW exhibits a high degree of stability, which is called the inertia of OEW to spectral emissivity. With the existence of this property, the approximation equation and temperature solution can be obtained by blackbody OEW in the case of unknown spectral emissivity. This serves as a fundamental basis for temperature measurement of targets with unknown spectral emissivity. To address the ambiguity in defining the inertia of OEW in this technique, a criterion for determining OEW inertia is proposed and verified by experiments. In this study, a parameter that quantitatively describes the approximation effects of the OEW is defined. By combining the discussion on the intersection of the approximation data and the reduced-channel signal under different approximation effects, an evaluation criterion for the OEW inertia is established through the definition of the confidence interval of the approximation effect. To macroscopically validate the correctness of the OEW inertia criterion, a simulation study is conducted to investigate the impact of the amplitude and FWHM of the spectral response function (SRF) on OEW inertia, based on this criterion. The correctness of the simulation results is confirmed through comparative experiments of temperature measurements on different SRF detectors, further demonstrating the correctness of the OEW inertia criterion.

Generalized inverse matrix-graphic deep learning algorithm for multispectral pyrometer temperature inversion.

The multispectral radiometric temperature measurement technique is affected by the unknown emissivity, and there is no multispectral radiometric temperature inversion algorithm applicable to any scene or target. To address the above problems, this paper converts the multispectral radiometric temperature inversion problem into an image recognition problem containing the temperature information to be measured, and proposes a graphical multispectral radiometric temperature adaptive inversion algorithm. In this paper, we use the difference between spectral channels to convert the one-dimensional radiation data into a two-dimensional radiation map; use the generalized inverse to obtain the spectral emissivity distribution features, fuse them with the two-dimensional radiation map, and use an improved deep learning network to achieve adaptive temperature inversion. It is experimentally verified that the algorithm proposed in this paper can achieve simultaneous inversion of temperature and emissivity for any scene or target with sufficient data set.

Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications

The directional spectral emissivity of a Ti–48Al–2Nb–2Cr alloy (in at.%), 4822 alloy, and a Ti-43.5Al–4Nb–1Mo-0.1B alloy (in at.%),TNM alloy, used in the aeronautical industry, are measured between 150 and 850 °C. The differences in the emissivity values between both alloys at the lowest temperatures, indicates that the βo phase, only present in TNM, exhibit higher emissivity values. By numerical integration of the measured data, the total directional and hemispherical emissivity have been calculated. At 850 °C the total hemispherical emissivity in vacuum are nearly identical with 0.274 ± 0.006 for the 4822 alloy and 0.273 ± 0.007 for the TNM alloy. The lower emissivity change with temperature measured in TNM alloys is related with the deconvolution of βo phase by diffusion processes. Afterwards, near-normal spectral emissivity measurements are performed in both alloys during isothermal oxidation treatments at 750 °C and 850 °C for 120 h. The emissivity data reveal that the TNM alloy exhibits higher oxidation resistance especially at 750 °C. In parallel, microstructural characterization has been performed before the measurements, after the directional emissivity measurements prior to oxidation and after isothermal oxidations. The formed oxide scale is composed of four layers that coincide with those reported in the literature: an outer layer of TiO2 contiguous with a layer of Al2O3, followed by a TiO2/Al2O3 mixed layer and finally a thin layer of Nb-rich nitride. This mixed layer governs the interferential part of the alloys’ emissivity spectra, which, in combination with the background, determines the overall radiative behavior of the alloys under service conditions.

Multi-band tunable strongly nonreciprocal thermal radiation in topological edge state coupled mode

Violating Kirchhoff's law of thermal radiation can break the reciprocity constraints on spectral emissivity and absorptivity, which provides new capabilities for managing photonic heat flow and fundamentally improves energy harvesting systems' efficiency. Currently, most micro-nano structures that violate Kirchhoff's law are mainly confined to single- or dual-band models, significantly limiting applications such as photonic energy conversion and thermal management. Here, a scheme is proposed for a topological one-dimensional photonic crystal heterostructure consisting of multiple photonic crystals and Weyl semimetals, and its absorptivity and emissivity are theoretically calculated by the transfer matrix method. The results show that the multi-band nonreciprocity that completely violates Kirchhoff's law can persist over broad angular and frequency ranges without requiring any external magnetic field via tuning the relevant parameters. Furthermore, the electric field distribution reveals that the formation of such multiple bands originates from the coupling between topological edge states, and the significant enhancement of the local field near the interface of the heterostructure provides favorable conditions for the realization of strong nonreciprocity. Our work may contribute to the design and development of multiband nonreciprocal devices for energy conversion and thermal management and may also provide design ideas for multiband reciprocal absorbers, filters, optical switching, etc.

Spectral regulation with high-temperature resistance by Mo-doped HfO2 monolayer for thermophotovoltaic systems

Structured spectrally selective emitters show good spectral performance in thermophotovoltaic (TPV) systems, but most of them cannot maintain good spectral emittance at high temperatures as expected. A Mo-doped HfO2 monolayer structure was proposed to improve the thermal stability of the structured emitters. A simulation model based on the transfer matrix method and effective medium theory was used to design the doped monolayer emitters. Thermal annealing and characterization measurements were conducted to investigate the proposed emitter after 1273 K–1473 K thermal annealing, and a TPV system model was built to evaluate their spectral performance after thermal annealing. The results revealed that 20% Mo doping can improve the spectral performance of a 90 nm HfO2 monolayer structure, making the spectral efficiency up to 60.93% at 1273 K. Due to the combined action of the Mo oxidation, grain growth and phase transition of HfO2 during thermal annealing, the formation of holes and Mo oxides were observed. Consequently, the spectral emittance of the doped emitters changed. Nevertheless, no obvious decline in the system efficiency (approximately 1%) of the TPV system with the doped emitter after 1273K thermal annealing for 12 h was observed. The proposed Mo-doped HfO2 monolayer emitter shows good spectral performance compared with the undoped one. The investigation of the thermal degradation of the proposed emitters can lay a foundation for promoting their applications of TPV systems.

Prediction of Isotropic Rough Surface Directional Spectral Emissivity with Surface-Morphology-Dependent Modelling

The surface directional spectral emissivity of rough metal surfaces in industry is of concern in infrared temperature measurement. In this research, the height and slope possibility density functions are introduced as variables, and the directional spectral emissivity of isotropic rough surface is modelled accordingly. The model is designed to derive the directional spectral emissivity of rough metal surfaces from the surface morphology (possibility distribution of the height and slope) and the material property parameters (refractivity). Then, a sandblasted surface is taken as a case study. The sandblasted surface morphology is measured. A Polynomial surface is proposed to describe the sandblasted surface morphology and is compared with a Gaussian surface and a Cox–Munk surface. Finally, the directional spectral emissivity measurement and infrared temperature measurement are conducted. It is shown that the predicted directional spectral emissivity and measured temperature with the surface-morphology-dependent isotropic rough surface directional spectral emissivity model have high precision. In this work, the possibility distribution of the height and slope of the surface is introduced as independent variables to provide better accuracy compared to the reported models. In some cases, the error of the infrared temperature measurement could be reduced to 20% (80 degrees, compared to Gaussian surface). This work contributes to improving the accuracy of IR temperature measurement of rough surfaces.

Oxidation induced emissivity variations of the Haynes 25 alloy at high temperatures

Haynes 25 alloy is used in the design of propulsion systems for spacecrafts and it can constitute a space debris at the end of life of the mission. All the thruster combustion chambers and nozzles are manufactured with Haynes 25 alloy and the thrusters used storable monopropellant hydrazine. During the atmospheric reentry of thruster pieces at high velocity, the Haynes 25 alloy is submitted to high temperatures in an extreme environment with atomic oxygen. This is why the high temperature oxidation of Haynes 25 was studied, in air plasma conditions in the temperature range 1000–1700 K. Moreover, as emissivity is an important parameter to know for the heat transfer, the spectral directional emissivity was measured on several samples surfaces: pristine, pre-oxidized in air plasma and in situ oxidized in air. The high temperature oxidation of Haynes 25 is moderate up to 1500 K and above an important mass loss occurred up to 1700 K (around 40 mg/cm2), that is the determined melting temperature. The emissivity of pristine Haynes 25 is vey low, around 0.20 at 1350 K and it increases with oxidation up to 0.85–0.90 at 1600 K.

Multi-objective fractional-order particle swarm optimization algorithms for data processing of multi-wavelength pyrometer.

This paper focuses the algorithm of the true temperature inversion for high-temperature targets with unknown emissivity by transforming multi-spectral true temperature inversion into multi-objective minimum optimization. Two improved fractional-order particle swarm optimizations (IFOPSO), high-order nonlinear time-varying inertia weight (Hntiw) IFOPSO and global-local best values (Glbest) IFOPSO, are proposed to obtain the true temperature by solving the multi-objective minimum optimization. Combining the inherent advantages of fractional-order calculus to jump out of the local extreme value, the Hntiw IFOPSO algorithm is proposed by replacing the linear time-varying inertia weights with nonlinear functions related to the total number of iterations and the current number of iterations. The Glbest IFOPSO algorithm is designed by using the global local optimal inertia weight and acceleration constant to update the particle velocity and position values, which improves the multi-objective optimization ability and the accuracy of the true temperature inversion. The effectiveness of the proposed methods is verified by the simulation with typical spectral emissivity models and the measured data from rocket tail flame.

Multi-band infrared camouflage compatible with radiative cooling and visible colors via a simple multilayer film structure

Conventional infrared camouflage materials are typically confined to special spectral ranges. To address challenges posed by the combination of both active and passive detection operating in different bands, a multi-band compatible camouflage material is highly required. Combining rigorous coupled-wave analysis and genetic algorithm, a 9-layer film structure composed of 3 thermally stable materials (SiO2, Ge and TiO2) on a quartz substrate is designed, which achieves multi-band infrared camouflage compatible with radiative cooling and visible colors. Specifically, the structure exhibits low average emissivity of 0.12 and 0.21 in the two atmospheric window bands of 3∼5 µm and 8∼14 µm, while it shows spectral emissivity favorable of radiative cooling (an average of 0.67) in the non-atmospheric window band of 5∼8 µm. The structure also achieves high absorptivity at two widely applied laser wavelengths of 1.06 µm (Nd:YAG lidar) and 10.6 µm (CO2 lidar). In addition, by manipulating the thickness of the top layer, the structure exhibits tunable visible colors covering green, blue and yellow, et al., without much influence on the above selective absorption and emission in the infrared bands. The multi-band selective absorption/emission characteristic is also applicable to large incident/emission angles. The underlying physics are analyzed in detail. The selective emission in the mid-infrared band is mainly caused by the forbidden bands formed by the multilayer film, while the high absorption at both laser wavelengths is attributed to the Fabry-Perot resonance supported in the structure and the intrinsic absorption of the materials. Finally, the overall camouflage performance of the structure is evaluated to make the results more intuitive. The significance of this work lies in the balance between the multi-band compatibility and structural simplicity of camouflage materials.

Influence of the oxidation on the optical properties of Mo-Si-Ti, Ta-Mo-Cr-Al and Ta-Mo-Cr-Ti-Al alloys

Three refractory element-based alloys were oxidized for 6 h at 1100 °C in air inside a muffle furnace and the way the oxidation, especially through the evolution of the surface composition and roughness, affects the optical properties of these materials is discussed here. The ternary Mo-20.0Si-52.8Ti (at%) serves as an example of Mo-based alloys, while the equimolar Ta-Mo-Cr-Al (TMCA) and Ta-Mo-Cr-Ti-Al (TMCTA) are typical of the class of oxidation-resistant refractory compositionally complex alloys. The normal spectral emissivity of these three samples was increased due to the oxidation process. Oxidized TMCA and TMCTA exhibit a solar absorptivity higher than that of state-of-the-art Ni-based alloys used for solar receivers in concentrated solar power plants. Thus, the two refractory compositionally complex alloys are considered promising candidates for solar thermal energy conversion application.

Simultaneous Control of Spectral And Directional Emissivity with Gradient Epsilon-Near-Zero InAs Photonic Structures.

Controlling both the spectral bandwidth and directionality of emitted thermal radiation is a fundamental challenge in contemporary photonics. Recent work has shown that materials with a spatial gradient in the frequency range of their epsilon-near-zero (ENZ) response can support broad spectrum directionality in their emissivity, enabling high total radiance to specific angles of incidence. However, this capability is limited spectrally and directionally by the availability of materials with phonon-polariton resonances over long-wave infrared wavelengths. Here, an approach is designed and experimentally demonstrated using doped III-V semiconductors that can simultaneously tailor spectral peak, bandwidth, and directionality of infrared emissivity. InAs-based gradient ENZ photonic structures that exhibit broadband directional emission with varying spectral bandwidths and directional ranges as a function of their doping concentration profile and thickness are epitaxially grown and characterized. Due to its easy-to-fabricate geometry, it is believed that this approach provides a versatile photonic platform to dynamically control broadband spectral and directional emissivity for a range of emerging applications in heat transfer and infrared sensing.

Validation of MODIS Temperature and Emissivity Products Based on Ground-Based Mid-Wave Hyperspectral Imaging Measurement in the Northwestern Plateau Region of Qinghai, China

The climatic fluctuations in northern China exhibit remarkable variability, making it imperative to harness the power of MODIS data for conducting comprehensive investigations into the influences of desertification, desert expansion, and snow and ice melting phenomena. Consequently, the rigorous evaluation of MODIS land surface temperature (LST) and land surface emissivity (LSE) products takes on a momentous role, as this provides an essential means to ensure data accuracy, thereby instilling confidence in the robustness of scientific analyses. In this study, a high-resolution hyperspectral imaging instrument was utilized to measure mid-wave hyperspectral images of grasslands and deserts in the northwest plateau region of Qinghai, China. The measured data were processed in order to remove the effects of sensor noise, atmospheric radiation, transmission attenuation, and scattering caused by sunlight and atmospheric radiation. Inversion of the temperature field and spectral emissivity was performed on the measured data. The inverted data were compared and validated against MODIS land surface temperature and emissivity products. The validation results showed that the absolute errors of emissivity of grassland backgrounds provided by MCD11C1 in the three mid-wave infrared bands (3.66–3.840 μm, 3.929–3.989 μm, and 4.010–4.080 μm) were 0.0376, 0.0191, and 0.0429, with relative errors of 3.9%, 2.1%, and 4.8%, respectively. For desert backgrounds, the absolute errors of emissivity were 0.0057, 0.0458, and 0.0412, with relative errors of 0.4%, 4.9%, and 3.9%, respectively. The relative errors for each channel were all within 5%. Regarding the temperature data products, compared to the inverted temperatures of the deserts and grasslands, the remote sensing temperatures provided by MOD11L2 had absolute errors of ±2.3 K and ±4.1 K, with relative errors of 1.4% and 0.7%, respectively. The relative errors for the temperature products were all within 2%.

A multilayer film based on thin-film interference and impedance matching for dual-laser and infrared stealth as well as thermal management

Multispectral compatible stealth encounters higher challenges and requirements with the combined application of multiple detection technologies. This paper proposes a multilayer film based on thin-film interference and impedance matching to achieve 1.06 µm and 1.54 µm dual-laser stealth and mid-wavelength infrared (MWIR, 3–5 µm) and long-wavelength infrared (LWIR, 8–14 µm) stealth, as well as thermal management by the non-atmospheric window (5–8 µm). The multilayer film consists of Al2O3, Fe3O4, ZnS, Ge and Ag layer (Al2O3/ZnS/Ge/Ag/Fe3O4/Ag) and the optical performance of multilayer film is calculated using the finite-difference time-domain (FDTD) method. The numerical results indicated that the spectral emissivity of the multilayer film is lower than 27 % in the MWIR and 14 % in the LWIR and the spectral absorptances are both over 98 % at the laser wavelength 1.06 µm and 1.54 µm, respectively, as well as in the non-atmospheric window. Moreover, the optical performance of the multilayer film could be influenced with incident angle whether it is TM or TE wave but independent of the polarization angle. This work provides theoretical guidance for design and optimization of multilayer film that processes the compatibility of infrared stealth in the MWIR and LWIR and dual-laser stealth with thermal management in the non-atmospheric windows.