Improved Properties of Optical Surfaces by Following the Example of the “Moth Eye”

Lohmüller, Theobald; Brunner, Róbert; Spatz, Joachim P.

doi:10.5772/8782

Cited by 4 publications

(2 citation statements)

References 49 publications

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“…If regarded in an effective medium approximation—which takes into account only the averaged refractive index of a given layer—the presence of the conical protrusions is equivalent to a so-called ‘index matching layer’, which has the role of reducing reflection when light enters from a medium with a lower index of refraction (for air n = 1) into one with higher index of refraction (for chitin n = 1.56), thus increasing the absorption of light in the scale lower lamina, which in the brown scales contains melanin pigment ( Lohmueller et al 2010 ), and likely in the orange scales ommochrome pigment ( Stavenga et al 2014 ). In transmitted light the blue scales are more transparent, indicating a reduced pigment content ( Fig.…”

Section: Resultsmentioning

confidence: 99%

The Only Blue Mimeresia (Lepidoptera: Lycaenidae: Lipteninae) Uses a Color-Generating Mechanism Widely Applied by Butterflies

Bálint

Sáfián

Hoskins

et al. 2018

Journal of Insect Science

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The butterfly Mimeresia neavei (Joicey & Talbot, 1921) is the only species in the exclusively African subtribal clade Mimacraeina (Lipteninae: Lycaenidae: Lepidoptera) having sexual dimorphism expressed by structurally blue-colored male and pigmentary colored orange–red female phenotypes. We investigated the optical mechanism generating the male blue color by various microscopic and experimental methods. It was found that the blue color is produced by the lower lamina of the scale acting as a thin film. This kind of color production is not rare in day-flying Lepidoptera, or in other insect orders. The biological role of the blue color of M. neavei is not yet well understood, as all the other species in the clade lack structural coloration, and have less pronounced sexual dimorphism, and are involved in mimicry-rings.

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Section: Resultsmentioning

confidence: 99%

The Only Blue Mimeresia (Lepidoptera: Lycaenidae: Lipteninae) Uses a Color-Generating Mechanism Widely Applied by Butterflies

Bálint

Sáfián

Hoskins

et al. 2018

Journal of Insect Science

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“…The second method, which yields a random ARSS (rARSS), consisted in direct etching of the optical element surface using process parameters suited to the respective substrate material. This work was performed using an Advanced Silicon Etcher machine and based on published dry etching recipes [6]. Excellent results were obtained on fused silica windows, fibers and lenses, Nd:YAG and Ho:YAG ceramics, along with spinel ceramic windows.…”

mentioning

confidence: 94%

High Damage Threshold Anti-reflection Surfaces Based on “Motheye” Nano-structures

Sanghera

Frantz

Busse

et al. 2015

Laser Ignition Conference

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The direct nano-structuring of the surfaces of an optical element is nowadays a well-established technique used primarily to enhance the light transmission through that optical element. Typically periodic or quasiperiodic in nature, these anti-reflective surface structures (ARSS) can be designed to generate strong interference effects over large bandwidths [1,2], to work in various materials [3] and to exhibit additional characteristics such as high laser damage thresholds [4]. The period of the pattern should be on a subwavelength scale and the height of the individual features on the wavelength scale to avoid the undesired diffraction effects (as the period becomes close to the wavelength of interest) while providing the required phase change (or optical impedance matching between the air, in the typical case, and the optical element), respectively. Modeling of these structures is typically done using rigorous coupled-wave analysis RCWA methods although the effective-index method can also provide reasonable insight (it cannot however model through the diffraction edge region) [5]. We will present a review of our work on surface nanostructuring of many technologically important optical materials and components and illustrate record-low reflectivity losses, large bandwidth and record-high laser damage thresholds.Surface nanostructuring was performed through two principal methods. The first method, which yields a periodic anti-reflective surface structure (ARSS), requires the surface to be resist-patterned through UV lithography followed by dry-etching which transfers the resist pattern into the substrate surface. Fused silica windows, Nd:YAG and Ho:YAG crystals, along with spinel ceramic windows have been processed in this fashion. This work was performed using holography-based patterning followed by dry-etching [3]. The second method, which yields a random ARSS (rARSS), consisted in direct etching of the optical element surface using process parameters suited to the respective substrate material. This work was performed using an Advanced Silicon Etcher machine and based on published dry etching recipes [6]. Excellent results were obtained on fused silica windows, fibers and lenses, Nd:YAG and Ho:YAG ceramics, along with spinel ceramic windows. A third method, based on embossing was also developed for IR fiber end faces. Nickel and silicon stamps with periodically patterned structures were made using lithographic techniques and then pressed onto heated fiber end faces to leave an imprint of the structure on the fiber end face. SWS or straight walled structures were also fabricated.Figures 1 to 5 show specific data for flat silica windows. Other samples include silica lenses; silica optical fibers; infrared optical fibers; polycrystalline ceramic spinel; ceramic laser materials; single crystal laser materials; Sapphire and Germanium.

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„Zwerge“ aus dem Minilabor

Marmé

Aupperle‐Pauls

Pauls

et al. 2014

Chemkon

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Zusammenfassung: Die Nanotechnologie in all ihren Facetten wird für die moderne Gesellschaft immer wichtiger und gilt als eine der Schlüsseltechnologien des 21. Jahrhunderts. In diesem Artikel werden schulgerechte Synthesen von Gold-und Silber-Nanopartikeln mit Hilfe eines Minilabors vorgestellt, die im außerschulischen Lernort, im Schüler-praktikum oder auch im Rahmen grçßerer Projekte eigenständig durchgeführt werden kçnnen. Außerdem wird ein schülerzentriertes Konzept für eine Nanotechnologie-Unterrichtseinheit vorgestellt, welches auf den Erwerb von den in den Bildungsplänen geforderten Schlüsselkompeten-zen zielt und den Schülerinnen und Schülern einen Einblick in den Wissenschaftsalltag und in wissenschaftliche Arbeitsund Vorgehensweisen geben soll.Stichworte: Gold-und Silber-Nanopartikel · Redoxreaktionen · Tyndall-Effekt Dwarf particles out of a Mini Lab -Synthesis of metallic nanoparticlesAbstract: Nanotechnology and its broad range of applications are becoming more and more important for modern society. It is said to be one of the key technologies of the current century. This article shows ways of implementing nanotechnology in schools. The presented syntheses of gold and silver nanoparticles were carried out in a miniaturized lab and adapted for use in class. They are appropriate to be carried out by the pupils themselves in school or in science centers, in brief or in longer projects. Furthermore, a student-centered teaching concept for a complete nanotechnology unit focused on key qualifications as claimed by the national curricula is presented. Students can learn about scientific work methods and get an insight view of scientific daily routine.

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Improved Properties of Optical Surfaces by Following the Example of the “Moth Eye”

Cited by 4 publications

References 49 publications

The Only Blue Mimeresia (Lepidoptera: Lycaenidae: Lipteninae) Uses a Color-Generating Mechanism Widely Applied by Butterflies

The Only Blue Mimeresia (Lepidoptera: Lycaenidae: Lipteninae) Uses a Color-Generating Mechanism Widely Applied by Butterflies

High Damage Threshold Anti-reflection Surfaces Based on “Motheye” Nano-structures

„Zwerge“ aus dem Minilabor

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