Films with Tunable Graded Refractive Index Consisting of Spontaneously Formed Mesoporous Silica Nanopinnacles

Shin Kitamura, Yosuke Kanno, Masatoshi Watanabe, Masahiko Takahashi, Kazuyuki Kuroda, Hirokatsu Miyata

    Research output: Contribution to journalArticle

    17 Citations (Scopus)

    Abstract

    Coatings with surfaces packed with pointed projections with subwavelength sizes are known as "moth-eye", whose graded index structure gives superior antireflection (AR) properties with a small dependence on wavelength and incident angle. However, the optical interface between the AR coating and a substrate still causes reflection, unless the refractive index of the coating is matched to that of the substrate. Here, we show a new AR coating with both graded and tunable refractive index, which completely eliminates distinct optical interfaces. The coating is made of a mesoporous silica film, whose surface is spontaneously converted to an assembly of pointed nanostructure by reactive ion etching, and its refractive index is matched universally to that of a substrate by controlled incorporation of titanium dioxide into the mesopores. This AR coating enables universal ultralow reflection on a substrate over the index range from 1.2 to 1.8 and will be applied widely in practical optics. (Figure Presented).

    Original languageEnglish
    Pages (from-to)47-52
    Number of pages6
    JournalACS Photonics
    Volume1
    Issue number1
    DOIs
    Publication statusPublished - 2014 Jan 15

    Fingerprint

    Refractometry
    Silicon Dioxide
    Antireflection coatings
    antireflection coatings
    Refractive index
    Silica
    refractivity
    silicon dioxide
    Substrates
    coatings
    Coatings
    Moths
    Nanostructures
    moths
    Reactive ion etching
    titanium oxides
    Titanium dioxide
    Ions
    Optics
    assembly

    Keywords

    • antireflection
    • film
    • index matching
    • mesoporous
    • moth-eye
    • subwavelength structure

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Atomic and Molecular Physics, and Optics
    • Biotechnology
    • Electrical and Electronic Engineering

    Cite this

    Films with Tunable Graded Refractive Index Consisting of Spontaneously Formed Mesoporous Silica Nanopinnacles. / Kitamura, Shin; Kanno, Yosuke; Watanabe, Masatoshi; Takahashi, Masahiko; Kuroda, Kazuyuki; Miyata, Hirokatsu.

    In: ACS Photonics, Vol. 1, No. 1, 15.01.2014, p. 47-52.

    Research output: Contribution to journalArticle

    Kitamura, Shin ; Kanno, Yosuke ; Watanabe, Masatoshi ; Takahashi, Masahiko ; Kuroda, Kazuyuki ; Miyata, Hirokatsu. / Films with Tunable Graded Refractive Index Consisting of Spontaneously Formed Mesoporous Silica Nanopinnacles. In: ACS Photonics. 2014 ; Vol. 1, No. 1. pp. 47-52.
    @article{7ea1d99554ea4031b47800952f337654,
    title = "Films with Tunable Graded Refractive Index Consisting of Spontaneously Formed Mesoporous Silica Nanopinnacles",
    abstract = "Coatings with surfaces packed with pointed projections with subwavelength sizes are known as {"}moth-eye{"}, whose graded index structure gives superior antireflection (AR) properties with a small dependence on wavelength and incident angle. However, the optical interface between the AR coating and a substrate still causes reflection, unless the refractive index of the coating is matched to that of the substrate. Here, we show a new AR coating with both graded and tunable refractive index, which completely eliminates distinct optical interfaces. The coating is made of a mesoporous silica film, whose surface is spontaneously converted to an assembly of pointed nanostructure by reactive ion etching, and its refractive index is matched universally to that of a substrate by controlled incorporation of titanium dioxide into the mesopores. This AR coating enables universal ultralow reflection on a substrate over the index range from 1.2 to 1.8 and will be applied widely in practical optics. (Figure Presented).",
    keywords = "antireflection, film, index matching, mesoporous, moth-eye, subwavelength structure",
    author = "Shin Kitamura and Yosuke Kanno and Masatoshi Watanabe and Masahiko Takahashi and Kazuyuki Kuroda and Hirokatsu Miyata",
    year = "2014",
    month = "1",
    day = "15",
    doi = "10.1021/ph400036a",
    language = "English",
    volume = "1",
    pages = "47--52",
    journal = "ACS Photonics",
    issn = "2330-4022",
    publisher = "American Chemical Society",
    number = "1",

    }

    TY - JOUR

    T1 - Films with Tunable Graded Refractive Index Consisting of Spontaneously Formed Mesoporous Silica Nanopinnacles

    AU - Kitamura, Shin

    AU - Kanno, Yosuke

    AU - Watanabe, Masatoshi

    AU - Takahashi, Masahiko

    AU - Kuroda, Kazuyuki

    AU - Miyata, Hirokatsu

    PY - 2014/1/15

    Y1 - 2014/1/15

    N2 - Coatings with surfaces packed with pointed projections with subwavelength sizes are known as "moth-eye", whose graded index structure gives superior antireflection (AR) properties with a small dependence on wavelength and incident angle. However, the optical interface between the AR coating and a substrate still causes reflection, unless the refractive index of the coating is matched to that of the substrate. Here, we show a new AR coating with both graded and tunable refractive index, which completely eliminates distinct optical interfaces. The coating is made of a mesoporous silica film, whose surface is spontaneously converted to an assembly of pointed nanostructure by reactive ion etching, and its refractive index is matched universally to that of a substrate by controlled incorporation of titanium dioxide into the mesopores. This AR coating enables universal ultralow reflection on a substrate over the index range from 1.2 to 1.8 and will be applied widely in practical optics. (Figure Presented).

    AB - Coatings with surfaces packed with pointed projections with subwavelength sizes are known as "moth-eye", whose graded index structure gives superior antireflection (AR) properties with a small dependence on wavelength and incident angle. However, the optical interface between the AR coating and a substrate still causes reflection, unless the refractive index of the coating is matched to that of the substrate. Here, we show a new AR coating with both graded and tunable refractive index, which completely eliminates distinct optical interfaces. The coating is made of a mesoporous silica film, whose surface is spontaneously converted to an assembly of pointed nanostructure by reactive ion etching, and its refractive index is matched universally to that of a substrate by controlled incorporation of titanium dioxide into the mesopores. This AR coating enables universal ultralow reflection on a substrate over the index range from 1.2 to 1.8 and will be applied widely in practical optics. (Figure Presented).

    KW - antireflection

    KW - film

    KW - index matching

    KW - mesoporous

    KW - moth-eye

    KW - subwavelength structure

    UR - http://www.scopus.com/inward/record.url?scp=84901404457&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84901404457&partnerID=8YFLogxK

    U2 - 10.1021/ph400036a

    DO - 10.1021/ph400036a

    M3 - Article

    AN - SCOPUS:84901404457

    VL - 1

    SP - 47

    EP - 52

    JO - ACS Photonics

    JF - ACS Photonics

    SN - 2330-4022

    IS - 1

    ER -