The UVBS18-2 UV Beamspliter is a 50.0 mm diameter, 4.00 mm thick UV Fused Silica beamsplitter with 30/70 reflection/transmission ratio optimized for 45° angle of incidence. This beamsplitter is designed for UV applications covering spectral range from 250 nm to 450 nm, featuring low absorption and excellent thermal stability. The back surface of the beamsplitter has a wedge that is less than 5 arc minutes to reduce undesired interference effects caused by the back reflections from both surfaces of the optics.
| Model | UVBS18-2 |
|---|---|
| Shape | Round |
| Type | UV Beamsplitter |
| Material | UV Grade Fused Silica |
| Diameter | 1.97 in. (50.0 mm) |
| Thickness | 0.16 in. (4.0 mm) |
| Surface Quality | 60-40 scratch-dig |
| Surface Accuracy | ≤1 λ at 632.8 nm over the clear aperture |
| Angle of Incidence | 45°±3° |
| Antireflection Coating | 250-450 nm AR coated |
| Coating (First surface) | Rabs: 50 ± 5 @ 350nm, Ravg: 50 ±10% over 250-450 nm |
| Coating (Second surface) | AR (Rave <1%, Ravg <2% over 250-450nm) |
| Diameter Tolerance | +0.0/-0.2 mm |
| Thickness Tolerance | +0.0/-0.2 mm |
| Transmission | 70%, independent of polarization |
| Efficiency | Ravg < 1%, Rabs < 2% @ 250-450 nm |
| R/T Ratio (%) | 30R/70T |
| Parallelism | < 5 arc minutes |
| Chamfers Angle/Tolerance | 45° ±15° |
| Clear Aperture | > central 85% of diameter |
| Cleaning | Non-abrasive method, acetone or isopropyl alcohol on lens tissue recommended see Care and Cleaning of Optics |
