Calcium Fluoride(CaF2) Double-Convex(DCX) Lenses, Uncoated/AR@3~5μm
Calcium Fluoride (CaF₂) Double Convex Lenses are high-performance optical lenses fabricated with premium calcium fluoride as the base substrate. Featuring a broad transmission spectrum from 180 nm to 8.0 μm, CaF₂ offers a high laser damage threshold, low fluorescence and excellent optical homogeneity. Although the material is relatively soft and prone to surface scratches, it is widely used for laser collimation and serves as an ideal substrate for various precision optical components.
With a positive focal length and two convex surfaces of equal curvature, double convex lenses precisely focus light into a single focal point. Their symmetrical design delivers optimal aberration correction for optical systems with a conjugate ratio between 5:1 and 1:5, while plano-convex lenses are recommended for applications outside this range. Tuniu Optics provides CaF₂ double convex lenses in a full range of sizes and focal lengths, available in uncoated and anti-reflection (AR) coated options. Broadband AR coatings optimized for the 3–5 μm IR1 infrared waveband are offered to maximize transmittance for different application scenarios. Custom lens specifications are available to meet bespoke requirements.
Parameters
| Material | CaF2 single crystal |
| Design Wavelength | 587.6 nm |
| Diameter Tolerance | + 0.0/ -0.1 mm |
| Center Thickness Tolerance | ± 0.1 mm |
| Focal Length Tolerance(EFL) | ± 1% |
| Centering Tolerance | < 3 arcmin |
| Surface Quality | 60-40 |
| Bevel | 0.2 mm X 45° |
| Coating | Uncoated, Ravg < 1.5%@3~5 μm |
Model
| Dia., mm | Coating | EFL, mm |
| 12.7 | Uncoated/Double-Sided-AR@3~5 μm | 15.00/20.00/40.00 |
| 25.4 | Uncoated/Double-Sided-AR@3~5 μm | 25.40/50.00/75.00/100.00/200.00 |

