K9 Optical Glass | Chinese Crown Optical Glass Substrate - Felix Glass
- Share
- publisher
- Felix Glass Co., Limited
- Issue Time
- Oct 21,2026
Summary
K9 optical glass is domestic crown optical glass equivalent to N-BK7. Felix Glass supplies precision K9 lenses, windows, prisms and blanks with AR coatings for visible & near-infrared optical systems.
K9 Optical Glass
K9 optical glass is the widely used domestic crown optical glass, optically equivalent to N-BK7. It delivers stable optical performance, excellent homogeneity and low striae, which is a cost-effective substrate choice for visible and near-infrared optical designs.
Key Optical & Physical Properties
| Parameter | Specification |
|---|---|
| Transmission Range | 350 nm – 2.2 μm |
| Refractive Index (@632.8nm) | 1.5168 |
| Abbe Number | 64.17 |
| Knoop Hardness | 610 Knoop |
| Density | 2.51 g/cm³ |
| Coefficient of Thermal Expansion | 7.1 ×10⁻⁶ /K |
Common Optical Components We Fabricate
- K9 spherical lenses: plano-convex, plano-concave, biconvex and biconcave lenses
- K9 optical flat windows, cover plates and protective substrates
- Right-angle prisms, equilateral prisms, beam splitter prisms
- Custom K9 blanks, optical wedges and gauge flats
Available Coating Options
We provide standard coatings optimized for K9 visible and near-infrared optical parts:
- Broadband AR coating for visible band 400–700 nm
- Single wavelength AR coating for 532nm, 633nm, 1064nm
- VIS-NIR anti-reflection coating
- Aluminum / chromium reflective coating for prisms and mirrors
Typical Application Fields
- Machine vision and industrial inspection optics
- Optical laboratory and teaching experimental equipment
- Low-power visible laser alignment and beam shaping
- Optical measurement instruments, autocollimators
- Consumer imaging and general optical assemblies
Machining Capacity & Quality Control
Felix Glass processes premium grade K9 optical glass with strict internal inspection. Surface scratch-dig grade up to 20/10, surface flatness can reach λ/10 @632.8 nm. We support round, square, rectangular and angled K9 optics, with tight angular and dimensional tolerance for prototype sampling and bulk production orders.
Datasheet & Custom Inquiry
Download our K9 glass datasheet for full dispersion curve and optical parameters. Send your technical drawing, target wavelength and coating requirements to get your custom quotation.
Request Datasheet & Custom Quote