A biconcave spherical lens has two concave spherical surfaces, a thin center and thick edges. It is a negative or diverging lens. The centers of curvature are on opposite sides, usually with approximately equal radii (R₁≈R₂<0). Center thickness is less than edge thickness, so it cannot converge light or form a real image by itself. Common specifications include outside diameters of 10-50 mm, focal lengths from −15 mm to −200 mm and a typical center thickness of 2 mm. Materials include BK7, fused silica and CaF₂, with visible, near infrared or infrared antireflection coatings available. Its negative focal length (f<0) causes parallel rays to diverge from a virtual focus on the incident side, where their backward extensions intersect. As a singlet it has longitudinal chromatic aberration: the absolute focal length decreases at shorter wavelengths, with blue light diverging more strongly than red. Negative spherical aberration can compensate positive spherical aberration from converging lenses to improve overall image quality. A single lens can diverge a collimated beam to about 25°, with a beam expansion ratio >10×. At any object distance it forms an upright, reduced virtual image on the same side as the object, with negative image distance. A ray parallel to the principal axis refracts so that its backward extension passes through the virtual focus, while a ray through the optical center is undeviated. The intersection of their backward extensions locates the top of the virtual image. Imaging follows the Gaussian formula 1/f = 1/v − 1/u, with f and v negative.
XZOP was founded in 2015, headquartered in Shenzhen, mainly engaged in R&D and sales. The factory covers an area of 4,500 square meters and has more than 60 employees. Its core business focuses on the processing of optical components, and the R&D, production, and sales services of coating products. It is a technology enterprise specializing in optical components, spectral technology, and application development. The main equipment of the factory includes: automatic cutting machines, profiling machines, inner circle cutting machines, milling machines, polishing machines, single and double side grinding machines, coating machines, etc. Testing equipment includes spectrophotometers, 2D measuring equipment, interferometers, microscopes, etc. The factory fully implements ISO9001 and ISO14000 standards and has formulated the quality policy of "efficient production, rapid response, prevention first, continuous improvement, mutual cooperation, good use of resources, continuous improvement, and common development".
Products are mainly used in biometrics, laser systems, machine vision, biochemical medicine, projection display, digital imaging, photoelectric sensors, optical communication, aerospace, and other fields.
Main products include:
1. Traditional optical coating products: anti-reflection lenses, beam splitters, high-reflection mirrors, dichroic mirrors, polarizers, attenuators, narrowband filters, long and short wave pass filters, etc.;
2. Laser optical coating products: laser mirrors, laser cavity mirrors, laser windows, laser beam combiners, laser protective lenses, laser galvanometer lenses, etc.;
3. Precision optical coating products: fluorescence filters, biochemical filters, OD6 high cutoff filters, projection optical machine filters, infrared optical components, etc.;
4. Special functional thin film products: hydrophobic films, anti-fingerprint films, ITO films, anti-fog films, waterproof films, etc.
5. Window panel products: special-shaped window glass, AG etched glass panels, infrared transmission windows, high-temperature resistant glass, tempered silk-screen panels, UV-resistant window glass, etc.
6. Optical lens products: convex lenses, concave lenses, achromatic cemented lenses, cylindrical lenses, ball lenses, aspherical lenses, etc.
7. Optical prism products: right-angle prisms, roof prisms, Dove prisms, pentagonal prisms, PBS cube beam splitter prisms, wedge prisms, etc.
In addition to the above conventional products, we can also provide professional customization services according to specific customer needs.
XZOP follows the business purpose of "quality first, customer supreme" and the corporate philosophy of "integrity, efficiency, hard work, win-win", and wholeheartedly serves customers. In developing new varieties of optical components and opening up new application markets, we are willing to cooperate with friends at home and abroad to create a better future for the optical industry!