Marco Abbarchi | SOLNIL: How do you pattern high-performance optical ceramics like Titania without complex and damaging etching processes?
00:10:38 - 00:11:38
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How do you pattern high-performance optical ceramics like Titania without complex and damaging etching processes?
This clip introduces a novel fabrication technique: direct nanoimprint lithography (NIL) of sol-gel precursors. Instead of patterning a solid material, this process starts with a liquid sol-gel solution deposited on a substrate. A mold is then applied directly to the wet film, physically shaping it into the desired three-dimensional nanostructure with high fidelity.
The key transformation step is calcination. After the imprinting, a thermal annealing process converts the soft, patterned sol-gel into a hard, dense, and environmentally stable inorganic ceramic. This elegant method completely bypasses the need for traditional, often difficult, and potentially damaging dry etching steps that are typically required for patterning robust materials like titanium dioxide.
The process is highly versatile and scalable, representing a significant manufacturing advantage. It can create a wide variety of shapes—such as pillars, holes, and gratings—with a controllably thin residual layer. The technology has been demonstrated on 200mm wafers using commercial NIL equipment and can even be applied to curved surfaces like lenses, opening up applications in conformal optics and AR glasses.
In this short video, you can learn:
* The process of direct nanoimprint lithography (NIL) on liquid sol-gel materials.
* How a calcination step transforms the imprinted gel into a hard, functional ceramic.
* The scalability of the process to 200mm wafers and its applicability to curved surfaces.
📋 **Clip Abstract** This video explains a powerful method for fabricating complex nanostructures from high-performance ceramics without any etching. Discover how direct nanoimprint lithography on a liquid sol-gel, followed by calcination, enables the scalable production of robust optical components on both flat and curved surfaces.
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#DirectNanoimprintLithography, #SolGelProcessing, #OpticalCeramics, #CeramicCalcination, #ARDisplays, #MicroLEDDisplays
This is a highlight of the presentation:
Direct Nanoimprint Lithography: Precision Patterning of purely Inorganic Compounds for Advanced Optical Materials
MicroLEDs, AR/VR Displays, Micro-Optics 2025: Innovations, Start-Ups, Market Trends
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MicroLED Connect
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00:04:26 - 00:06:36
How can you push an AR waveguide's field of view beyond 70 degrees without changing the waveguide material itself?
How can you push an AR waveguide's field of view beyond 70 degrees without changing the waveguide material itself?
This segment introduces a core material innovation: a sol-gel process to create a full spectrum of inorganic optical materials. The technology enables the production of everything from ultra-low refractive index (n=1.12) silica to ultra-high refractive index (n=2.6) titania. This wide, continuous tuning of refractive index is achieved simply by mixing two precursor solutions, offering unprecedented design flexibility for optical components.
The key performance metrics of these materials are detailed, highlighting their suitability for demanding applications like AR. They offer extremely high transparency across the visible spectrum, with scattering losses well below 0.1%, even at the highest refractive index of 2.57. This performance level, achieved through a simple liquid deposition process, can even outperform conventional vacuum-based methods like atomic layer deposition (ALD).
The clip explains the critical application for AR waveguides. A high refractive index in the waveguide core is essential for a large field of view (FoV). Once the core material is maxed out, the only way to further increase the FoV is by decreasing the refractive index of the cladding. By providing both record-high index titania for the core/gratings and record-low index silica for the cladding, this technology enables the maximum possible index contrast, pushing FoV limits while using fully inorganic, environmentally stable materials.
In this short video, you can learn:
* The synthesis of inorganic optical materials with a tunable refractive index from 1.12 to 2.6.
* How to achieve ultra-high transparency (<0.1% scattering loss) in high-index films.
* The strategy of using high-index contrast (core and cladding) to maximize the field of view in AR waveguides.
📋 **Clip Abstract** This clip details a novel sol-gel approach for creating inorganic optical films with an unprecedented range of refractive indices (1.12 to 2.6). It explains how this extreme index contrast is critical for maximizing the field of view in augmented reality waveguides.
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#SolGelOptics, #TunableRefractiveIndex, #HighIndexContrast, #ARWaveguideFoV, #AugmentedRealityDisplays, #PrintedOptics
00:08:45 - 00:10:13
Your nanostructures produce vibrant colors in air, but they wash out when embedded in a protective matrix. What's the solution?
Your nanostructures produce vibrant colors in air, but they wash out when embedded in a protective matrix. What's the solution?
This segment explores the challenge of maintaining the performance of optical nanostructures, like Mie resonators, when they are encapsulated for protection. When a high-index resonator (e.g., titania) is surrounded by a conventional material like standard silicon dioxide (n≈1.45), the reduced refractive index contrast dampens the optical resonances. This degradation leads to spectrally broad and weak responses, resulting in desaturated, washed-out colors.
The solution presented is to embed these high-index nanostructures within an ultra-low refractive index matrix. By using a sol-gel derived silica with a refractive index of just 1.12, the system behaves almost as if the resonators are in air. This high-contrast environment preserves the high-quality factor (Q-factor) of the resonances, keeping them sharp and bright, which is essential for creating vivid colors.
The practical result is demonstrated using a CIE color gamut chart. Structural colors created with high-index titania pillars embedded in conventional SiO2 are clustered near the white point, indicating poor saturation. In contrast, the same pillars embedded in the ultra-low index (n=1.12) silica produce highly saturated primary colors that cover a much wider area of the color gamut, enabling vibrant, high-fidelity color displays from passive nanostructures.
In this short video, you can learn:
* Why refractive index contrast is critical for sharp Mie resonances in nanostructures.
* How an ultra-low index (n=1.12) encapsulation material can preserve optical performance.
* The direct impact of high index contrast on achieving a wide color gamut with structural colors.
📋 **Clip Abstract** Learn why embedding nanophotonic structures for protection often kills their performance and how an ultra-low refractive index (n=1.12) matrix solves the problem. This clip shows how maximizing index contrast preserves sharp optical resonances, enabling highly saturated structural colors for next-gen displays.
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#StructuralColor, #RefractiveIndexContrast, #UltraLowIndexMatrix, #MieResonators, #MicroLEDDisplays, #ARDisplays