Refractive index database

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Optical constants of CDGM - ZF (Dense flint)

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: 7.92e-07 2.05e-08 2.6e-11 1.28e-06 3.74e-10 0.232
nd: 1.672707
Vd: 32.180986
glass_code: 673322
glass_status: preferred
density: 4.08 g/cm3
  - temperature_range: -30 70 °C
    coefficient: 8.5e-06 K-1
  - temperature_range: 20 300 °C
    coefficient: 9.5e-06 K-1
dPgF: -0.0014
climatic_resistance: 1.0


CDGM Zemax catalog 2022-06 (obtained from
See also CDGM optical glass data sheets


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SF5 optical glass

SF5 is a type of optical glass characterized by its high refractive index and moderate to high dispersion, indicated by a lower Abbe number. This makes it particularly useful in applications where significant light bending capabilities are needed, such as in the design of compact lenses. However, the higher dispersion means that it tends to separate different wavelengths of light more than other types of glass, which can lead to chromatic aberration if not properly managed. To counteract this, SF5 is often paired with other types of optical glass in complex lens systems to optimize performance across a range of wavelengths. Common applications for SF5 glass include high-quality camera lenses, microscopes, and other optical instruments where precise image quality is paramount. Though it is generally more expensive than standard optical glasses like BK7, its specialized properties make SF5 a valuable resource for optical designers aiming to achieve superior optical performance.

SF5 and similar glasses produced by different makers

Maker Glass
Schott N-SF5
Hikari E-SF5
Sumita K-SFLD5

CDGM Glass Co., Ltd.

CDGM Glass Co., Ltd. is a leading manufacturer of optical glass based in China. The company offers a wide range of optical materials, including various types of crown and flint glasses, which are used in applications ranging from consumer electronics to advanced scientific instruments. Known for their capacity for large-scale production as well as their commitment to quality, CDGM has positioned itself as a major player in both domestic and international markets. Their optical glass products are often used in lenses, prisms, and other optical components that require high precision and reliability. With an extensive catalog that caters to different optical requirements, such as high refractive indices or low dispersion, CDGM serves a diverse clientele including manufacturers of microscopes, telescopes, cameras, and other high-precision optical equipment. The company's expertise in glass science and its ability to provide customized solutions have made it a go-to supplier for businesses seeking high-quality, reliable optical glass.

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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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