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Optical constants of HIKARI - BK (Borosilicate crown)
J-BK7A

Wavelength: µm
 (0.280–2.400)  
 

Complex refractive index (n+ik)[ i ]


n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula

$$n^2=2.27110883-0.00938988354λ^{2}-0.000100277081λ^{4}+0.0109572221λ^{-2}+0.000120210067λ^{-4}+3.31079774\text{×}10^{-06}λ^{-6}-1.48235581\text{×}10^{-08}λ^{-8}$$

Conditions & Spec sheet

n_is_absolute: false
wavelength_is_vacuum: false
temperature: 23.0 °C
thermal_dispersion:
  - type: "Schott formula"
    coefficients: 8.20811e-07 8.68946e-09 -1.28363e-13 5.04167e-07 5.18196e-10 0.147522
nd: 1.516800
Vd: 64.129950
density: 2.51 g/cm3
thermal_expansion:
  - temperature_range: -30 70 °C
    coefficient: 7.4e-06 K-1
dPgF: -0.001
phosphate_resistance: 1.0

References

NIKON Zemax catalog 2017-11 (obtained from http://www.nikon.com)
See also HIKARI glass data sheets

Data

[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]

INFO

BK7 optical glass

BK7 is a widely used optical glass known for its high transmission and clear, colorless appearance. Composed primarily of silica and boron oxide, BK7 is popular in a broad range of optical applications, including lenses, prisms, and windows. It exhibits good mechanical properties and can be easily polished to a high optical quality. While it is not as resistant to thermal shock or chemical corrosion as some specialized glasses like borosilicate or fused silica, it is considerably less expensive, making it a cost-effective choice for many applications. Its relatively high refractive index and low dispersion make it suitable for a variety of optical systems, particularly those operating in the visible spectrum. Because of its versatility and cost-effectiveness, BK7 is often considered the "go-to" material for general-purpose optical components.

Analogs of BK7 glass produced by different makers

Maker Glass
SCHOTT N-BK7
OHARA S-BSL7
HIKARI J-BK7A
CDGM H-K9L
HOYA BSC7
SUMITA K-BK7
LZOS K8

External links


Hikari Glass Co., Ltd.

Hikari Glass Co., Ltd. is a Japanese company specializing in the manufacturing of high-quality optical glass and optical components, and is a subsidiary of Nikon Corporation. Known for its precision engineering and strict quality control, Hikari serves various industries including consumer electronics, scientific research, and industrial optics. The company offers a wide range of specialized optical materials, including various types of crown and flint glasses, which are used in applications demanding high levels of optical clarity and performance. Hikari's products often find use in lenses, prisms, and other optical elements where precision and reliability are critical. With the backing of Nikon's renowned expertise in optics and imaging, Hikari has become a respected name in the field of optics, serving both domestic and international markets. Their expertise in crafting custom solutions for complex optical requirements has made them a preferred choice for organizations in need of specialized glass materials. As a testament to their commitment to quality, Hikari Glass Co., Ltd. is often sought after for projects requiring the highest levels of optical performance and integrity.

External links


Glass

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.

External links