Optical constants of BK7
K-BK7 (SUMITA)
Wavelength:
µm
(0.290–2.000)
Complex refractive index (n+ik)
n
k
LogX
LogY
eV
Derived optical constants
Dispersion formula
$$n^2=2.2705778-0.010059376λ^{2}+0.010414999λ^{-2}+0.00028872517λ^{-4}-2.2214495\text{×}10^{-05}λ^{-6}+1.4258559\text{×}10^{-06}λ^{-8}$$Conditions & Spec sheet
n_is_absolute: false
wavelength_is_vacuum: false
temperature: 20.0 °C
thermal_dispersion:
- type: "Schott formula"
coefficients: 6.84e-07 2.05e-08 -1.55e-10 4.18e-07 2.74e-10 0.178
nd: 1.51633
Vd: 64.1
glass_code: 516641
density: 2.52 g/cm3
thermal_expansion:
- temperature_range: -30 70 °C
coefficient: 6.3e-06 K-1
- temperature_range: 20 300 °C
coefficient: 8.5e-06 K-1
dPgF: -0.0014
climatic_resistance: 1.0
acid_resistance: 1.0
References
SUMITA Zemax catalog 2017-02-02 (obtained from http://www.sumita-opt.co.jp)
See also SUMITA optical glass data book
Data
INFO
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.External links
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 |