K9 (BK7) is a borosilicate crown glass that has become the preferred substrate for most optical components due to its balanced optical properties, stable physical and chemical properties, and extremely high cost-effectiveness.
1. Imaging optical system
Various types of lenses: used in the lens assembly of mobile phones, digital cameras, and security monitoring equipment to produce convex and concave lenses for focusing, zooming, and aberration correction;
Observation equipment: as the objective and eyepiece of telescopes and sights, as well as the core optical components of microscopes;
Display projection: Form a projector lens group to ensure clear and sharp projected images.
2. Prism type components
Turning prism: such as the Paul prism in binocular telescopes, which uses total reflection to fold the optical path and correct the mirror image;
Splitting prism: used in laser experiments and optical measurements to divide a beam of light into multiple beams in proportion. The low dispersion characteristic of K9 (BK7) can reduce the color difference effect after splitting.
3. Application of laser technology
As the base material for low to medium power laser mirrors, output mirrors, and beam expanders, it can be used after surface coating with optical thin films. It is widely used in laser marking, cutting, and welding equipment, and the cost is much lower than special materials such as quartz.
4. Precision measurement and scientific research instruments
Optical reference: As an optical flat crystal, it is a reference measuring tool for detecting the flatness of workpieces;
Interferometer components: For example, the splitter plate and compensation plate of the Michelson interferometer are made of K9;
Window protection film: The front protection window of microscopes, spectrometers, and CCD cameras isolates dust and moisture while ensuring light transmission. The light transmission range covers 350nm-2100nm, fully meeting the testing requirements from visible light to near-infrared region.
5. Filter substrate
The vast majority of bandpass and cutoff optical filters are coated on K9 glass substrates and are the core substrates for machine vision and mobile phone camera modules (such as infrared cutoff filters).