Optical constants of BK7
Complex refractive index (n+ik)
n k LogX LogY eV
Derived optical constants
Conditions & Spec sheet
n_is_absolute: false wavelength_is_vacuum: false temperature: 25.0 °C thermal_dispersion: - type: "Schott formula" coefficients: 1.7e-06 1.43e-08 -4.27e-11 4.08e-07 6.74e-10 0.201 nd: 1.516330 Vd: 64.142022 glass_code: 516641 density: 2.52 g/cm3 thermal_expansion: - temperature_range: -30 70 °C coefficient: 7.2e-06 K-1 - temperature_range: 20 300 °C coefficient: 8.6e-06 K-1 dPgF: -0.0024 climatic_resistance: 1.0 acid_resistance: 1.0 phosphate_resistance: 2.0
OHARA Zemax catalog 2017-11-30 (obtained from http://www.ohara-inc.co.jp)
See also OHARA glass data sheets
Ohara GroupOhara Group is an international group of companies with headquarters in Japan and subsidiaries in Japan (Ohara, Inc.), United States (Ohara Corporation), and Germany (Ohara, GmbH). Ohara is known for its specialization in high-quality optical glass, ceramics, and other advanced materials. With a history spanning over a century, Ohara has been at the forefront of optical innovations, producing a wide range of specialized glass types including low-dispersion and high-refractive-index materials. These are used in various demanding applications like telescopes, microscopes, and high-performance camera lenses. The company's commitment to research and development has led to groundbreaking products such as low thermal expansion glass-ceramics and other specialty materials used in semiconductor manufacturing and space telescopes. With stringent quality control procedures, Ohara ensures that its optical glass meets the highest standards of clarity, consistency, and performance. Their materials are widely regarded for their exceptional quality and are often used in scientific research, aerospace, and other fields where precision and reliability are paramount. Ohara's reputation for technical excellence and innovation makes it a key player in the global optics and materials science industries, providing cutting-edge solutions for a range of complex applications.
BK7 optical glassBK7 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