The function of the N-BK7 window with λ/10 flatness is to transmit light radiation between two different environments, while preventing interference from other environmental substances.
The window does not change the wavelength distribution of the light, the wavefront characteristics of the transmission, and does not cause the scattering of the light.
The N-BK7 window produced by Crysmit Optoelectronics has the advantages of low deformation, low scattering and high parallelism.At the same time,our engineers will help you with a special coating design.
CRYSMIT can offer λ/10 flatness N-BK7 windows for high precision instrument application.
| Part NO.: | Thickness | Flatness | Parallelism | |
| N-BK7 Window 01 | 12.7 mm | 1.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 02 | 12.5 mm | 1.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 03 | 12.7 mm | 2.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 04 | 12.5 mm | 2.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 05 | 20.0 mm | 4.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 06 | 20.0 mm | 5.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 07 | 25.4 mm | 5.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 08 | 25.0 mm | 5.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 09 | 25.4 mm | 6.35 mm | λ/10 | 30 arcsec |
| N-BK7 Window 10 | 25.0 mm | 6.35 mm | λ/10 | 30 arcsec |
| N-BK7 Window 11 | 50.8 mm | 6.35 mm | λ/10 | 30 arcsec |
| N-BK7 Window 12 | 50.8 mm | 8.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 13 | 50.0 mm | 8.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 14 | 76.2 mm | 10.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 15 | 76.2 mm | 12.7 mm | λ/10 | 30 arcsec |
| N-BK7 Window 16 | 101.6 mm | 12.7 mm | λ/10 | 30 arcsec |
| N-BK7 Window 17 | 101.6 mm | 15.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 18 | 127.0 mm | 15.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 19 | 127.0 mm | 20.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 20 | 152.4 mm | 20.0 mm | λ/10 | 30 arcsec |
| N-BK7 Window 21 | 154.2 mm | 25.0 mm | λ/10 | 30 arcsec |
Understanding the features of N-BK7 Window ?
Optical Transmission: N-BK7 glass offers high transmission from 350nm to 2,000nm, making it suitable for applications in the visible and near-infrared spectrum.
Index of Refraction: N-BK7 has a refractive index of about 1.517 at 587.6 nm (the green spectral line of mercury), making it a good choice for lenses and other optical components.
Thermal Stability: N-BK7 has good thermal stability, with a coefficient of thermal expansion of about 7.1 x 10^-6 K^-1.
Chemical Resistance: N-BK7 has a moderate chemical resistance. It's not recommended for use in environments with strong acids, alkalis, or in situations where it would be exposed to water for long periods of time.
Durability and Hardness: It has good hardness and is resistant to physical damage and scratches, making it suitable for a wide variety of applications.
Ease of Fabrication: N-BK7 is relatively easy to shape and polish into precision optical components, including windows, lenses, prisms, and mirrors.
Cost-Effective: Compared to other optical materials, N-BK7 is relatively cost-effective.
Abbe Number: N-BK7 has an Abbe number of 64.17. This is a measure of the material's dispersion (color spreading), with a higher Abbe number indicating less dispersion.
CRYSMIT's N-BK7 windows Standard Speficication
| Attribute | Specification |
| Typical Diameter (Φmm) | 10.0, 12.7, 15.0, 20.0, 25.4, 30.0, 50.8,76.2,101.6 |
| Square Shape:WxH(mm): | 12.7x12.7,25.4x25.4,30x30,50.8x50.8 |
| Typical Thickness (mm) | 1.0, 2.0, 3.0, 4.0, 6.35,12.7,15,20 |
| Diameter Tolerance (mm) | +0/0.05 |
| Thickness Tolerance (mm) | ±0.01 |
| Clear Aperture | >90% |
| Parallelism | 3 arc sec |
| Surface Quality | 10/5 |
| Flatness(@632.8nm) | λ/10 |
| Coating | Uncoated, AR, HR, PR Coating, etc. |
The flatness report for N-BK7 Heterosexual Windows：
