This PDF file contains the front matter associated with SPIE Proceedings Volume 11696, including the Title Page, Copyright Information, and Table of Contents.

Welcome and Introduction to SPIE Photonics West OPTO conference 11696: Advanced Fabrication Technologies for Micro/Nano Optics and Photonics XIV

In this abstract, I will discuss our efforts in realizing ultra-sharp nanoantennas with radius of curvature of 1 nm and 5 nm nanogap for extreme photon squeezing applications. Firstly, we propose an unconventional nanolithography technique called cascade domino lithography (CDL) to realize such sharp tip structures. By controlling collapse of micro/nanopillar photoresist structures, diverse plasmonic nanogap structures or single-digit nanometer scale structures can be realized, which are not obtainable with conventional nanofabrications. Secondly, we analyze the optical characteristics of sharp bowtie nanoantennas by using numerical simulations and near/far-field experiments. For instances, an extreme field localization and enhancement are verified by finite-difference time-domain (FDTD) simulations along with near-field scanning optical microscopy (NSOM) measurement, nonlinear spectroscopy and surface-enhanced Raman spectroscopy (SERS).

Slanted gratings show high efficiency in coupling light into waveguides, which is critical for optics such as the diffractive optical elements (DOEs) used in augmented reality glasses. Fabrication of master molds used for producing slanted gratings require high etch selectivity between SiO2 and a metal mask. The industry standard for trench etch, Reactive Ion Etch (RIE), cannot produce slanted trenches. In this work, we demonstrate the fabrication of surface relief grating (SRG) master molds with slant angles of 30, 45 and 60 degrees. Using Reactive Ion Beam Etch (RIBE), etch anisotropy is controlled via the directionality of the ion beam, combined with angle of incidence. The selectivity between metal mask vs SiO2 can be tuned (7:1 to 12:1). An in-house oxygen cleaning increases stability, leading to high repeatability in process and etch rates. High static uniformity across the wafer surface was achieved using a proprietary tunable ion source.

Fresnel incoherent correlation holography (FINCH) is a super-resolution incoherent imaging technique built on the principle of self-interference. In FINCH, the object wave is split into two, modulated by diffractive lenses with different focal distances and interfered to generate the hologram. At least three holograms with different phase-shifts between the two object waves were recorded and combined to synthesize a complex hologram. The different planes of the object were reconstructed by numerically propagating the complex hologram to one of the focal planes of the diffractive lenses. FINCH, in general, has a higher lateral resolution but lower axial and temporal resolutions than direct imaging. A new approach inspired by guide-star holography techniques is applied to FINCH. In this study, two diffractive lens functions with different focal lengths have been spatially multiplexed into one using a binary quasi-random function and fabricated using electron beam lithography. In the first step, the point spread hologram library was recorded by axially scanning a point object along the optical axis. In the next step, an object hologram was recorded. The three-dimensional image of the object was reconstructed using a cross-correlation between the point spread hologram library and the object hologram. The modified approach increased the time resolution of FINCH by three times, improved the axial resolving power and enabled the development of the most compact version of FINCH. We believe that FINCH can be applied for monitoring bacterial cell shape during contact with mechanically biocidal nanotextured surface and light matter interactions.

A five-dimensional imaging technique to resolve objects in three-dimensional space, spectrum and time has been developed using a single diffractive optical element consisting of a quasi-random array of pinholes. The object space and spectrum were sampled by axially scanning a point object with different wavelengths along the optical axis and recording the corresponding spatio-spectral signatures. The recorded spatio-spectral signatures were catalogued and stored in a library. A thick object emitting light at different wavelengths was placed in the object space within the axial boundaries of the library and illuminated by light sources within the spectral boundaries of the spatio-spectral library and a single object intensity pattern was recorded. The spatio-spectral images of the object were reconstructed by processing the object intensity pattern and the spatio-spectral library in the computer. Depth-wavelength reciprocity was exploited to see colour from depth and depth from colour. A computational approach utilizing the scaling factors in image formation was used to synthesize the spatio-spectral signatures. The application of depth-wavelength reciprocity and the synthesis of spatio-spectral signatures accelerated the training procedure leading to a faster multidimensional multispectral imaging technology in comparison to the existing coded aperture holography techniques. The developed technology was implemented for spatio-spectral-temporal imaging of a fast transient event such as a spark with a temporal resolution of 40 μs. A single camera shot of the spark recorded by a monochrome high-speed camera was converted into intensity cube data along depth for different wavelengths.

Infrared radiation is by nature characterized by low photon energy and thus usually detected by semiconductor materials with small band gaps. These materials are usually produced by epitaxial growth processes. These achieve high performance but often at high cost. This motivates the development of alternative materials. Here, we aim to harness recent breakthroughs in nano-optics and in two dimensional materials to realize photodetectors that are scalable, low cost and with good performance. We report our results with materials that include PtSe₂, Cu TCNQ, bP/MoS₂, SeTe, and graphene. We furthermore report on filter array – detector array (FADA) microspectrometers.

In this talk, we discuss our recent experimental efforts on nanostructured metasurfaces to manipulate the optical wavefront using advanced lithographic techniques. In the talk, we will discuss their functionalities for augmented reality, wavefront structuring and control, filtering, spectrometry, polarimetry, and others. We will also discuss the opportunities and challenges to scale these nanostructured surfaces to larger dimensions using alternative fabrication techniques.

Dielectric metasurfaces have shown a great potential as ultrathin optical components, but practical use is still hindered by limitations of conventional nanofabrication methods. Here, we develop a highly-productive printing-based scalable nanofabrication method to manufacture dielectric metasurfaces at low cost. This method features a nanoparticle composite in which optical properties can be controlled by the content of nanoparticles, so high-efficiency metasurfaces can be fabricated by only a single step of printing without any secondary operations such as thin film deposition and etching. The feasibility of our method is also verified by realizing high-efficiency metaholograms and metalenses working in the visible and near-infrared regime.

Recently, several nanostructures have been proposed as a route for structural coloration. However, these demonstrations suffer from severe angle and polarization sensitivity and are impractical to integrate with industrial standards. Here, we present an approach to structural coloration that exploits the strong hybridization of localized and cavity modes of a layer of self-assembled plasmonic nanoparticles in near-field proximity to a mirror. Our approach offers a large-scale and low-cost process, that can be applied to different types of substrates offering a highly versatile colorization solution that can be exploited for biosensing, displays, or as-is for producing structural color paint.

Infrared (IR) microspectroscopy is a powerful molecular fingerprinting tool widely used for the identification of structural and functional composition of biological and chemical samples. The IR microspectroscopy beamline at the Australian Synchrotron can be operated either with a single-point narrow-band mercury cadmium telluride (MCT) detector or a focal plane array (FPA) imaging detector with 64 × 64 pixels. For the implementation of indirect nonscanning imaging technology, the system was operated with the FPA detector. In this study, we propose an indirect IR imaging technique based on the principles of correlation optics using diffractive optical elements such as random pinhole array (RPA) and Fresnel zone plate (FZP). The spatial and spectral variations of point spread functions (PSFs) of the RPA and FZP were simulated for the synchrotron configuration. Intensity responses for 2D objects were simulated using the same simulation conditions and reconstructed using Lucy-Richardson algorithm. Fabrication of diffractive elements for IR wavelengths is often a challenging task as the IR transparent material substrates, such as barium fluoride and calcium fluoride, are highly susceptible to thermal shocks and brittle by nature. The diffractive elements were fabricated by ablating directly on a 100 nm thick gold coated substrate using femtosecond laser pulses. The simulation results and the fabrication outcomes demonstrate the feasibility of indirect imaging at the synchrotron IR beamline.

Plasmonic nanostructures provide an excellent platform for label-free detection and manipulation of molecules based on their physical and spectral properties. Our recently discovered superchiral light on achiral plasmonic substrates was used to demonstrate enantioselective chiral molecule detection that are relevant to the pharmaceutical industry. The talk will focus on the detection of chiral drugs and biomolecules using a degenerate cavity-coupled plasmonic substrate. We also discuss advances made regarding the enantioselective separation of chiral molecules using plasmonic tweezers and prospective technical challenges that we aim to address in the future.

Due to the high cost and requirement for cryogenic cooling of Mercury Cadmium Telluride (MCT) detectors, there is a growing demand for cheap Long Wavelength Infrared (LWIR) detectors at room temperature. Graphene has shown great potential yet suffers from a low absorption (<3%) in the LWIR ranges. In this presentation, we demonstrate the asymmetric plasmon-assisted hot carrier generation and Seebeck photodetection in nano-patterned Graphene with an enhanced absorption (>60%). This novel Graphene photodetector exhibits a remarkable responsivity of 2900 VW-1, detectivity of 1.1 x 109 Jones with a fast response of 100ns in 8-12 μm band at room temperature.

High refractive index provides various benefits such as miniaturization of optical elements, enhancement of resolution for imaging techniques and utilization for transformative optics. In line with this, a lot of efforts have been taken to engineer and increase the refractive index (n). Especially, metamaterials have enabled to extremely increase the refractive index beyond the naturally occurring materials [1,2]. However, the high-index metamaterials, developed thus far, has been mainly limited to the regime of the relatively low frequency due to their easy-to-craft features (e.g., n of 38.64 at THz and ~1800 at microwave) [3,4]; an increase in n beyond the natural limit is yet to be achieved at optical regimes. The monolithic lithography, which has been a major tool for the development of the metamaterials, would be difficult to satisfy the requirements for achieving unnaturally high n at optical range, including the arraying of sub-100 nm building blocks with a few nm-gaps over the

In this work, we explore a new bottom-up approach based on plasmon-assisted hydrothermal synthesis (PAHS) to achieve localized growth of zinc oxide (ZnO) in hybrid nanophotonic devices. By engineering gold nanogap antennas, we achieve efficient control over the localization and enhancement of both the electric field and the generated heat. A nanobutterfly antenna is designed to achieve both polarization-dependent heat localization and localized electric field enhancement. A few-nm-thick ZnO layer is grown at the targeted location of the nanogap antenna thanks to selective plasmonic heating. We also numerically study the back-action induced by the material synthesis on the heat generated by the antenna and show how PAHS can be used as a self-limited growth method. The PAHS method opens new perspectives for the design and fabrication of hybrid nanophotonic devices.

We have demonstrated UV laser photo-polymerization of elastic 2D/3D structures using UV-curable Polydimethylsiloxane (PDMS). In this technique, UV curable PDMS was locally polymerized to fabricate 1D and 2D single layer structures, as well as 3D multi-layer structures with resolution in micrometer-scale and structure dimension in millimeter-scale. In addition, a hybrid technique of aerosol jet printing followed by UV-LDW was developed to realize 2D patterning of thinner UV curable PDMS layer on free-form surface without solvents. In addition, 3D micro/nano processing for fabrication of 3D microfluidic surface-enhanced Raman spectroscopy (SERS) sensors will be presented as a subtractive process using photo-sensitive glass.

Micro/nano electro-mechanical systems (MEMS/NEMS) are constantly attracting an increasing attention for their relevant technological applications in fields ranging from biology, medicine, ecology, energy to industry. Most of the performances of micro-nanostructured devices rely on both the design and the intrinsic properties of the constituent materials that are processed at such dimensional scale. For this reason, spatial precision, resolution and reproducibility are crucial factors in the micro-fabrication procedure. 3D direct laser lithography (DLL), based on multiphoton absorption, allows to realize outstanding three-dimensional structures with nanoscale features. This technique has recently emerged as a powerful tool for fabricating 3D micro-patterned surfaces for optics, photonics, as well as for bioinspired cell culture scaffold. We propose a method for a two-step fabrication of micro/nanostructured multicomponent systems to be employed as transductors, by means of the integration of 3D DLL and shadowing effects in metal deposition. A z-axis accelerometer is the proof-of-concept for the validation of the proposed transductor. The former is composed of a cantilever patterned with conductive paths which act as a strain gauge. Mechanical stimulation deforms the cantilever and, accordingly, varies its conductive properties. The fabrication of the conductive components is performed using the vacuum evaporation of gold, a traditional microfabrication technique, and exploiting the shadowing effect due to peculiar microstructures on the cantilever.

Complex 3D structures having lateral and depth resolutions of <1 µm and 20 nm, respectively, are fabricated in various polymers, including PMMA, ABS, CR-39, and others, by a direct photoablation process utilizing 172 nm radiation from flat microplasma-driven excimer lamps. The developed process does not require any toxic or photosensitive materials, and, therefore, may be performed outside of a clean room. The fabricated 3D structures may also serve as a master mold for PDMS and the curing of other materials.

Freeform microlens arrays, FMLAs, have gathered considerable scientific and industrial interest in recent years due to their advantages compared to the more standard MLAs, based on rotationally symmetric optical units. However, they pose are challenging to design and manufacture. More specifically, the complex surface shapes involved, typically described by a large set of parameters and the large number of individual microstructures in each FMLA makes their quality control cumbersome. Surface profile measurements involve many data points, difficult to handle and optical functionality tests provide little insight into potential manufacturing deviations. Here we present and demonstrate CAD-based characterization and design for manufacturing methods that at- tempt to overcome these limitations. We also present two additional CAD-based tools that analyze FMLA designs from a manufacturing perspective that we have developed to support optical designers and manufacturers alike to identify critical parts in an early stage. Our algorithms can process several hundreds of individualized microstructures in a couple minutes.

The optical tweezers platform provides an attractive approach for the fabrication of three-dimensional structures. Existing studies on optical tweezers assembly have mostly focused on the formation of small-scale structures consisting of a single type of dielectric building block. In this work, we demonstrate the potential of our automated optical positioning and linking (OPAL) platform that uses optical trapping for object manipulation and biochemical binding as a linking mechanism. We show a comprehensive analysis of system parameters and fabricate the largest microstructure built to date using this approach. Furthermore, we assemble multicomponent structures consisting of nanoscale building blocks.

The recent development of chalcogenide hybrid inorganic-organic polymers (CHIPs) based on the inverse vulcanization of sulfur and selenium with organic monomers provides a new materials platform for infrared photonics. These materials have high refractive indices (1.7 to 2.1), excellent transmission in the SWIR and MWIR, and compatibility with polymer processing techniques. The optimal fabrication processes for these materials depend upon the specific composition required for the target application, with polymer properties ranging from thermoplastic to thermoset. Significant progress has been made in fabricating bulk-optic and integrated photonics prototypes such as microlens arrays and single-mode optics building blocks.

Optically transparent polymers with a high refractive index can find a broad range of applications in optoelectronics. The majority of available polymers present lower refractive index values ranging from 1.50 to 1.60. Here, we demonstrate the development of organic polymers with a high refractive index (up to 1.90) for thin-film applications. The synthesized polymers show high transparency in the visible wavelength and are entirely nanoparticle free. They are among the organic polymers with the highest refractive index ever reported. The developed polymers can be nanopatterned via nanoimprint lithography, a powerful method to fabricate nanostructures following a simple and scalable process.

Bio-based materials obtained from renewable sources are emerging as they offer easy processing, fulfill technological, functional and durability requirements at the same time ensuring increased bio-compatibility, recycling, and eventually lower cost. Optical 3D printing (O3DP) is a rapid prototyping tool (and an additive manufacturing technique) being developed as a choice for efficient and low waste production method, yet currently associated with mainly petroleum-derived resins. We employ a single bio-based resin derived from soybean oil, suitable for O3DP in the scales from nano- to macro-dimensions, which can be processed even without the addition of photoinitiator. The approach is validated using both state-of-the art laser nanolithography setup as well as a widespread table-top 3D printers - sub-micrometer accuracy 3D objects are fabricated reproducibly using Asiga platform. Such concept is a breakthrough in rapid prototyping by switching the focus of O3DP to bio-based resins.

The interest for nanoimprint lithography (NIL) as enabling technology for applications in the field of photonics, solar, lighting and displays is growing. The quality, flexibility in design, the relative ease and competitive costs at which surfaces can be patterned makes NIL a groundbreaking technology. While the added value of imprinted light management crystallizes, the need for high-volume NIL production methods becomes more urgent. The Roll-to-Plate (R2P) imprint technology can enable mass volume production, having the opportunity for large area imprinting, manufacturing higher numbers of smaller products in a single imprint step. In this presentation the replication process and quality of the Morphotonics GEN5 R2P imprint equipment will be discussed.

With high contrast optical images, it is possible to write sub-diffraction limited features over large areas. The dimensions of these super-resolved lithographic features are a function of optical contrast and total dose. Writing uniform subwavelength features requires uniform dose, and therefore uniform recording intensity. Patterns written with Gaussian beams exhibit large linewidth variation within each exposure field, and we mitigate this by incorporating a refractive beam shaper. A beam shaper does improve uniformity; however, intensity noise remains an issue. To mitigate intensity noise, we show that it is possible to scan the beam while recording without washing out the interference pattern. This is accomplished with an interferometer that incorporated a diffraction grating as a beam splitter. To first order, this design is insensitive to beam pointing. That is, as pointing angle changes, the interference fringe positions remain fixed while the beam position moves. Scanning over the resist averages out intensity noise, dramatically improving uniformity. We demonstrate both experimentally and with models, linewidth variation across a field written with different recording strategies. Linewidth from a Gaussian recording beam varies by 32% center to beam waist. With the inclusion of refractive beam shaping, linewidth uniformity can be brought down to 13%. By incorporating scanning with beam shaping, linewidth uniformity can be further reduced to as low as 4%.

Photonic crystal patterns for light trapping in Si solar cells are developed via different process flows: 1) step-and-repeat projection lithography with lift-off or 2) laser ablation and subsequent etching dry or/and wet. Both methods are amenable for large area (2×2 cm²) fabrication and can be used to break the ray-optics light trapping limit. This is required to surpass the record high efficiency ∼ 26% of solar-to-electrical power conversion of Si solar cells and approach the theoretical limit of ∼ 30%. Also, standard electron beam lithography (EBL) was used to define Si₃N₄ or Cr masks for wet KOH etching on silicon-on-insulator (SOI) and Si wafers. Direct laser writing of the etch mask by ablation (10 nJ, 515 nm, 230 fs pulses) has an advantage due to its scalability. The large area patterning is important for industrial application of direct laser writing of light trapping patterns in solar cells and absorbers/emitters for the IR spectral range.

Substrate Conformal Imprint Lithography (SCIL) solves the limitations of PDMS soft-stamp based NIL techniques (resolution, pattern deformation, overlay) and allows low-pressure wafer scale conformal contact and sub-10 nm resolution using a novel silicone rubber stamp. SCIL demonstrated direct replication of sub-50nm patterns in silica over 200mm wafers with stamp lifetimes over 500 imprints. The evaluation of patterns on wafer scale is usually done by SEM or AFM, and not amendable to inline inspection. We will demonstrate a novel compact optical quality inspection method for nanophotonic components, based on Fourier microscopy (imaging the back-focal plane of objective lens). In combination with inverse modeling, we reach few-nanometer precision for periodic structures.

We present a fiber-based 3D printing system with the highest printing resolution. Fabricated lines and microstructures are presented too. A microlens (NA 0.9) is printed in the Nanoscribe 3D-printer and attached to the fiber. A femtosecond laser (780nm, 80MHz) is used for two-photon polymerization and the focused spot on the tip of the lens is generated by wavefront shaping with the Transmission Matrix method. The spot size (lens with NA 0.9) is compared to the spot size of the fiber (NA 0.29) and to the spot size obtained when a commercially available microlens is attached (NA 0.54). Exposure tests are conducted by printing lines or voxels on a photosensitive resin and finally a prepared high aspect ratio structure is used for demonstrating the utility of a fiber-3D printing system to reach confined areas for microfabrication.

First focus when developing imprint materials for optical applications is on their optical properties. However other properties are also key. Here we focus on the thermo-mechanical properties of polymer-based imprint materials and their importance for various applications. Special emphasis will be put on thermo-mechanical stress induced by thermal mismatch. We’ll compare thermo-mechanical bulk properties of such materials with results from FEM simulations and experimental tests.

Soft biomaterials have been proposed as outstanding candidates for soft micro-optics and photonics applications due to their optical transparency and unique biocompatibility. However, there is still lacking a facile strategy that can rapidly and biofriendly prototype biomaterials into micro-optics. Here, we present a novel method, digital micromirror device (DMD) based rapid photopatterning that can fabricate microfeatures on hydrogel within seconds. Several diffractive optics including transmission 1D/2D gratings, beam splitter, Fresnel Zone Plate lenses and computer-generated holograms were produced. The optical performance of these optical devices was characterized and indicates that this method enables prototyping user-defined micro-optics with high fidelity. This versatile photopatterning technique can therefore be a potential route to develop precise soft optical microfeatures using any photosensitive biomaterials.

Multi-material micro stereolithography systems based on single-photon and two-photon polymerization using multiple droplets have been developed. In the single-photon process, several types of photocurable resins are stored on a palette that is moved by a translation stage. Multi-material 3D microstructures are formed by accumulating each layer in z direction while exchanging the resins. Using this system, multicolor 3D microstructures were created with multicolor photocurable resins. In addition, a multi-material two-photon lithography system was also developed. Metamaterials and micro optical elements were fabricated using multiple photocurable resins. These multi-material micro stereolithography systems are useful to create functional microdevices.

We review our recent progress on laser-based 3D micro- and nanoprinting, including application examples, on (i) multi-material, and (ii) faster/scalable 3D printing. Regarding (i), we report on combining self-organization and 3D printing for light-scattering devices, stimuli-responsive liquid-crystal elastomer photoresists, and 3D polymer-metal architectures. Concerning (ii), we present a novel 3D chiral mechanical metamaterial with tailored characteristic length, composed of nearly 120 thousand complex unit cells, enabled by rapid multi-focus multi-photon 3D printing. We discuss more sensitive multi-photon photoresists for lower required laser powers. Furthermore, we outline the status of parallelized two-color 3D light-sheet laser microprinting using inexpensive continuous-wave lasers.

Here we report on the laser manufacturing of glass true 3D micro-optics. We demonstrate the feasibility of producing individual free-form geometry elements such as lenses, prisms, gratings proving the potential of integration into monolith stacked components. This is achieved by combining ultrafast laser 3D nanolithography and subsequent thermal post-treatment (calcination) - a novel approach introduced for additive manufacturing of inorganic materials [Nanoscale Horiz. 4, 647 (2019)]). The laser made pristine micro-optical components maintain their predefined shape while material is converted from hybrid polymer to glass corresponding to its inherent refractive index and transparency. This approach enables both realization of complex geometries and variation of material properties simultaneously.

Photonic crystal fibers (PCF) have revolutionized the field of optical fibers. Their unique properties, as endlessly single-mode operation, high birefringence, and hollow-core optical guidance, are enabled and controlled by their hole-array geometry. Thanks to these properties, optical waveguides based on geometrically unbound PCF designs could be exploited to realize miniaturized complex devices which implement advanced photonic operations. However, arbitrary PCF geometries are difficult or even impossible to produce using current PCF fabrication methods. Here, we show how to fabricate optical waveguide segments with PCF designs by 3D microprinting and how the combination of these segments can realize complex photonic devices.

For nowadays and future resolution calibration tasks of areal-optical measuring instruments, micro structures with nanometer details, covering as most as possible of these instrument’s characteristics, are needed. Since current calibration measures do not fully satisfy all of these characteristics, we report on a newly chirped topography, that allows for the very first time for a holistic analysis of all the required attributes. To realize this highly resolved micro structure, e.g., an aberration-free laser lithography system will become indispensable in near future. Therefore, we’ve implemented a Gerchberg-Saxton based algorithm, improving any focal intensity distribution by the use of a so-called double-helix.

Recently, we presented a simple 3D model based on a combination of disordered Bragg stacks capable to entirely mimic the optical properties of the scales of the white beetle Cyphochilus. Due to its simplicity, we use this model here to investigate numerically the influences of filling fraction and anisotropy on the scattering properties, which are under ongoing debate. Moreover, we present an experimental realization of our model and the first measurement of the entire photon lifetime distribution within the scales and our model as well. Appropriate simulations reveal strategies to design strongly scattering structures with tailored photon lifetime distributions.

Generally, an optical lens is reduced its reflection by multilayer anti-reflection coating. However, there are some problems, for example, those coatings cannot be attached for some kind of resins, and show clack or peeling by temperature change or humidity. Lately, anti-reflection effect by sub-wavelength structure on optical lens surface is studied widely. This is called ARS, Anti-Reflective Structure. ARS solved above problems, and has low dependence on incident angle of light. Conventionally, for mass production of ARS lens, we tried injection molding. That is, fabricating fine structure on mold core, and transfer the structure to plastic resin. However, the transferring is very difficult, because of its fineness and adhesion resin to the core. Besides, mold for high transcription is expensive. We tried to fabricate ARS on plastic lens surface by Reactive Ion Etching. Controlling plasma condition at each etching process cleverly, we successfully obtained fine ARS on optical lens surface. The structure has high aspect and narrow pitch which is about 0.1μm, and show good anti-reflective property.

Owing to their tunable electromagnetic properties, subwavelength structures such as metamaterials have enabled novel applications across fields of engineering. In particular, metal-insulator-metal (MIM) plasmonic metamaterials have demonstrated efficient light energy absorption based on localized surface plasmon resonances. Due to these properties, MIM plasmonic resonance structures present its potential applications for photon absorption or emission at elevated temperatures, such as thermophotovoltaics. However, majority of reported MIM plasmonic structures are built with materials with a lower melting point such as gold or silver. Therefore, there are needs to explore how refractory materials affect the resonance properties of MIM plasmonic structures for high-temperature applications. In this work, we numerically report MIM plasmonic metamaterials built with highly refractory materials. Based on finite-difference timedomain (FDTD) simulation results, light absorption of these metamaterials peaks as high as 99.9% at the wavelength of 8.3 μm. This strong, selective absorption is attributed to the localized surface plasmon resonance. The results of this study suggest that the applications of MIM plasmonic devices may be extended for higher-temperature environments.