A plano-concave lens is an optical lens with one concave surface and one flat surface. It has a negative focal length and is commonly used in light projection, beam expansion, or to increase the focal length of an optical system. Plano-concave lenses are essential in applications where a virtual image is required or when working with distant objects. They are often paired with convex lenses to form complete optical systems, utilizing the principles of the lens formula to achieve the desired results.
Shanghai Optics manufactures a wide variety of plano concave lenses optimized for the UV (ultraviolet), visible, and IR (infrared) spectrums. Our range includes options with AR coatings for enhanced performance. We also offer custom optical lenses, including bi concave lenses and double concave lenses, ideal for applications requiring light divergence or image formation from distant objects.
Our facility produces lenses ranging from 2.33 mm to 1000 mm in diameter, with both coated and uncoated options. Our design engineers can collaborate with you to develop custom convex and concave lenses tailored to your specific needs. Whether you’re looking to work with a convex lens or need specialized designs for your optical systems, we are equipped to meet your requirements.
Factory Standard
Specifications of our lenses include material, surface quality, clear aperture, diameter tolerance, thickness tolerance, and surface irregularity.
Contact us for manufacturing limit or custom specifications.
Specifications | Factory Standards | Manufacturing Limit |
Dimension Tolerance | +/-0.05mm | +/-0.01mm |
Center Thickness Tolerance | +/-0.05 mm | +/-0.01mm |
Radius Tolerance | +/-0.3% | +/-0.1% |
Surface Quality(S/D) | 40-20 | 10-5 |
Irregularity | 1/4 Lambda | < 1/10 Lambda |
Centration(arc min) | 3′ | 1′ |
The material substrate determines features such as hardness, scratch resistance, and transmission range. We offer plano-concave lenses in Schott, Ohara, and CDGM optical glass, as well as Corning 7980 fused silica, UV fused silica, infrared fused silica, calcium fluoride (CaF2), barium fluoride (BaF2), germanium, zinc selenide, and zinc sulfide. Each material possesses unique characteristics that influence performance.
The diameter tolerance of a plano-concave lens describes the acceptable range for the lens diameter. While it has no direct effect on the performance of the lens, it relates to how the lens is fitted into its mount or holder. Our factory standard for diameter tolerance is ±0.05 mm, with a manufacturing limit of ±0.01 mm.
The center thickness of a lens refers to the allowable variation in material thickness, measured at the exact mechanical axis of the lens, directly between its outer edges. This specification affects optimal performance because the lens thickness helps determine the optical path of light passing through the lens. Our factory standard for center thickness is ±0.05 mm, and our manufacturing limit is ±0.01 mm.
The clear aperture is the diameter of the portion of the lens that meets performance specifications. Manufacturing constraints mean the outer rim of a lens cannot be as clear as the critical inner aperture, but our factory standard ensures a clear aperture of greater than 95% of the central dimension.
The amount of decenter in a lens is defined as the physical displacement of the lens’s mechanical axis (i.e., geometric axis) from its optical axis. The optical axis is the line connecting the centers of curvature of the lens surfaces. Our factory standard for centration is less than 3 arc minutes, with a manufacturing limit of 1 arc minute.
Surface quality refers to the absence or presence of scratches, pits, and digs. In most applications, these are primarily cosmetic defects, but for high-powered laser applications, high surface quality is crucial, as these defects can increase energy absorption to a level that damages the optic. Surface quality is specified by a two-part scratch-dig number: the lower the number, the higher the quality. While 80-50 is generally considered standard quality, our factory standard is 40-20 (after coating). We can also provide extremely high-quality 10-5 plano-concave lenses at a cost premium.
Surface irregularity refers to how the shape of the surface deviates from that of the reference surface. Our factory standard for irregularity allows for less than ¼ lambda deviation, while our manufacturing limit is for less than 1/10 lambda.
In conclusion, Shanghai Optics is dedicated to manufacturing top-quality plano-concave lenses for various applications, including laser systems. With a wide selection of materials, stringent manufacturing standards, and the capability to create custom lenses, we are committed to meeting the diverse needs of our customers. Our lenses’ outstanding performance, combined with anti-reflection coatings and superior surface quality, makes them indispensable for reducing spherical aberration and achieving optimal results in various optical systems.
Please contact us to schedule a free consultation or request a quote for your next project.