Refractive index database

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Optical constants of SUMITA - SFLD

Wavelength: µm

Complex refractive index (n+ik)[ i ]

n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula


Conditions & Spec sheet

n_is_absolute: false
wavelength_is_vacuum: false
temperature: 20.0 °C
  - type: "Schott formula"
    coefficients: -5.51e-06 1.82e-08 -3.64e-10 1.08e-06 1.52e-09 0.28
nd: 1.78472
Vd: 25.9
glass_code: 785259
density: 3.3 g/cm3
  - temperature_range: -30 70 °C
    coefficient: 9.3e-06 K-1
  - temperature_range: 20 300 °C
    coefficient: 1.05e-05 K-1
dPgF: 0.0144
climatic_resistance: 1.0
acid_resistance: 1.0


SUMITA Zemax catalog 2017-02-02 (obtained from
See also SUMITA optical glass data book


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SF11 optical glass

SF11 is a specialized type of optical glass with a high refractive index and a relatively low Abbe number, indicating higher dispersion properties. This glass type is particularly useful in optical systems where substantial light bending is required, such as in telephoto lenses, high-magnification microscopes, and other compact optical assemblies. However, the high level of dispersion associated with SF11 can result in chromatic aberration, where different wavelengths of light are focused at different points. To correct for this, SF11 is often combined with other glass types that have lower dispersion in complex lens systems, aiming to achieve balanced chromatic correction. Its unique properties make SF11 a popular choice in high-performance optics where both a high refractive index and specific dispersion characteristics are necessary. While SF11 is generally more expensive than more conventional optical glasses like BK7, its specialized attributes make it invaluable in advanced optical designs that demand high levels of performance.

SF11 and similar glasses produced by different makers

Maker Glass
Schott N-SF11
Hikari E-SF11
Sumita K-SFLD11

SUMITA Optical Glass, Inc.

SUMITA Optical Glass, Inc. is a Japanese corporation known for its specialization in the production and development of optical glass, optical fiber, and various other photonic products. Founded in 1953, the company has established itself as a leading provider of high-quality optical materials that are used in a wide range of applications—from industrial and scientific optics to consumer electronics and medical devices. SUMITA's portfolio includes a variety of specialized optical glasses, including high-refractive-index, low-dispersion, and infrared-transmitting materials. These are often utilized in lenses, prisms, and other optical components requiring precision and high performance. With a strong commitment to research and development, SUMITA continually innovates to meet the evolving demands of the optics industry. Their rigorous quality control processes ensure that products meet the highest standards for optical clarity, consistency, and reliability. SUMITA Optical Glass, Inc. has garnered a reputation for excellence and innovation, making it a preferred supplier for organizations in need of advanced optical solutions.

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Glass is a versatile, amorphous material that has been an essential component in optical technologies for centuries. Comprising mainly of silica along with various additives like soda, lime, or boron, glass can be engineered to exhibit a wide range of optical properties, such as refractive indices and dispersion characteristics. In the optical industry, specialized types of glass like crown, flint, and extra-low dispersion (ED) glasses are used for manufacturing lenses, prisms, and other optical elements. These glasses are precisely formulated to offer specific properties, such as low chromatic aberration or high light transmittance across different spectral ranges. Glass can also be coated with thin layers of materials like anti-reflective coatings to enhance its optical performance. More recently, advances in photonics and nanotechnology have led to the development of innovative glass types, such as photonic crystal and metamaterial glasses, which exhibit unique light-manipulating properties. It is crucial to note that the optical properties of glass, including its refractive index, can vary depending on its composition and temperature, making it important to consult specific data for particular applications. Overall, glass remains a foundational material in optics, its wide applicability owed to its tunable properties and general robustness.

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