Home / Custom / Optical Components / Optical Spherical Lens / Double Concave Lens 
A double concave lens/mirror has a negative focal length, thereby causing collimated incident light to diverge. The double concave lens/mirror has an equal radius of curvature on both sides of the lens. They are generally used to expand light or increase focal length in the existing system, such as beam expander and projection systems.
Optical glass such as K9, fused silica, sapphire, MgF2, silicon (Si), ZnSe, ZnS, etc. These materials possess high transmittance, low absorption, low scattering, uniform refractive index, and specific dispersion characteristics.
Precisely hemispherical. The machining precision of the center and radius of curvature of the sphere is extremely high.
The surface is precision polished to an optical grade of 10-5 to ensure image quality and reduce scattering and aberrations.
An AR coating is typically applied to the concave surface to maximize the transmittance of specific wavelengths of light (e.g. visible light) and reduce reflection loss.
| Material | Optical glass/ Fused silica/ sapphire etc. |
|---|---|
| Diameter | 2mm~300mm |
| Diameter tolerance | ±0.05mm(≤50mm) |
| ±0.1mm(＞50mm) | |
| Focal length | -50mm~-2000mm |
| Focal length tolerance | ±0.2%（＜10mm） |
| ±0.5%（＜10mm-1000mm） | |
| ±1%（＜＞1000mm） | |
| Center Thickness | 2mm~20mm |
| Surface quality | 60/40， 40/20， 20/10 |
| Surface accuracy | λ/2~λ/10@632.8nm，532nm |
| Clear Aperture | >85% dig diameter |
| Centration | <3arc min~ 30arc sec |
| Coating | As per customer’s request |
| Material | Diameter (mm) | Surface Radius 1 (mm) | Surface Radius 2 (mm) | Center Thickness (mm) | Focal Length (mm) |
|---|---|---|---|---|---|
| H-ZK3 | 5 | -14.4 | -14.4 | 3 | -9.8 |
| H-ZF6 | 8 | -7.2 | -30.5 | 5 | -7.4 |
| H-K9L | 10 | -11.1 | -11.1 | 2 | -10.4 |
| JGS1 | 10 | -9.25 | -9.25 | 1.25 | -9.8 |
| H-ZF7LA | 11 | -11.9 | -11.9 | 2 | -7.1 |
| H-K9L | 12 | -25.1 | -25.1 | 1.26 | -24 |
| BAF3 | 12 | -19.5 | -47.1 | 2 | -23.4 |
| ZF11 | 12 | -12.6 | -12.6 | 3 | -7.4 |
| H-K9L | 12.5 | -103 | -103 | 1.5 | -98.9 |
| H-ZF6 | 13 | -30.6 | -154 | 3 | -33.5 |
| H-LAK7 | 13 | -48.9 | -27.7 | 2 | -24.4 |
| H-ZK2 | 13 | -12.1 | -15.7 | 1 | -11.3 |
| H-ZF6 | 13.5 | -34.7 | -79.6 | 1.5 | -31.6 |
| H-ZF2 | 14 | -36.2 | -192 | 3 | -45 |
| H-ZF6 | 14 | -34.7 | -79.6 | 3 | -31.6 |
| H-LAK53A | 14 | -31.7 | -58.8 | 1.5 | -27 |
| H-K9L | 14 | -27.9 | -32.2 | 2 | -19 |
| H-ZF6 | 15 | -23 | -27.7 | 2.8 | -16.4 |
| H-ZF6 | 15 | -27.5 | -23.6 | 7.23 | -16.4 |
| H-F3 | 15 | -50.5 | -11.3 | 1.5 | -14.8 |
| N-SF6 | 15 | -13.2 | -12.1 | 2 | -7.4 |
| H-ZF3 | 16 | -30.6 | -15.8 | 3 | -14.6 |
| H-LAF50B | 16.7 | -16.8 | -17.8 | 1.8 | -11 |
| H-LAF50B | 17.3 | -37.2 | -37.2 | 3 | -23.9 |
| H-K9L | 20 | -299 | -85.4 | 2 | -128 |
| H-ZF52A | 20 | -51.6 | -21 | 1.9 | -16.7 |
| H-ZF6 | 21 | -77.4 | -77.4 | 2.5 | -51 |
| H-ZF7LA | 21 | -42.6 | -184 | 4.064 | -42.8 |
| H-ZF7LA | 22 | -255 | -16.2 | 9 | -18.7 |
| H-K9L | 24 | -11.1 | -90 | 1 | -18.9 |
| JGS1 | 25 | -92.1 | -92.1 | 2.5 | -100 |
| H-K9L | 25 | -52.1 | -52.1 | 3.5 | -50 |
| H-LAF4 | 25 | -38.4 | -38.4 | 8.4 | -25.4 |
| H-F4 | 25 | -36.7 | -29.2 | 3 | -25 |
| ZK9 | 27 | -149 | -52.9 | 1.45 | -62.7 |
| H-ZK21 | 28.6 | -281 | -23.8 | 3 | -35 |
| BaK2 | 29.5 | -2249 | -80.2 | 2 | -143 |
| JGS1 | 30 | -71 | -71 | 3 | -77 |
| BaK2 | 30.5 | -2249 | -76.4 | 2 | -137 |
| H-ZF3 | 32 | -11.8 | -284 | 2 | -15.7 |
| ZF1 | 41 | -692 | -170 | 2.8 | -211 |
| ZF7L | 44 | -153 | -49 | 3 | -45.8 |
| ZF4 | 54 | -340 | -249 | 2.5 | -197 |
| H-ZF3 | 58 | -73.8 | -234 | 4 | -77.8 |
| F4 | 60 | -74.9 | -78.4 | 1 | -61.3 |
| ZF1 | 65 | -516 | -163 | 5.49 | -190 |
| ZBaF3 | 65 | -296 | -52.4 | 2.5 | -67.5 |
| H-ZF2 | 68 | -83.5 | -249 | 5.5 | -92.3 |
| F13 | 68 | -2465 | -41.8 | 3 | -65.6 |
| H-F4 | 72 | -170 | -71.8 | 12 | -80 |
| H-K9L | 90 | -102 | -347 | 6 | -15 2 |
en
English
