Composed of a plane and a concave spherical surface, it has a negative focal length and negative spherical aberration, enabling collimated incident light to diverge, forming only a virtual image seen through the lens. It is frequently used to extend beams, increase system length, and compensate for aberrations in other lenses within a system. It is widely used in display systems, projection systems, laser measurement, optical imaging, beam control, and other fields.
| Specifications | |
| Material | BK7 |
| Design Wavelength | 546.1nm |
| Design Index | 1.5183+/-0.0005 |
| Diameter Tolerance | +0.0，-0.15mm |
| Paraxial Focal Length Tolerance | +/-2% |
| Centration | 3 arc minute |
| Clear Aperture | >85% |
| Surface Figure | λ/4@632.8nm |
| Surface Quality | 60/40 |
| Bevel | 0.25mm*45° |
| Coating | Uncoated |
| Specifications | |
| Material | BK7 |
| Design Wavelength | 546.1nm |
| Design Index | 1.5183+/-0.0005 |
| Diameter Tolerance | +0.0，-0.15mm |
| Paraxial Focal Length Tolerance | +/-2% |
| Centration | 3 arc minute |
| Clear Aperture | >85% |
| Surface Figure | λ/4@632.8nm |
| Surface Quality | 60/40 |
| Bevel | 0.25mm*45° |
| Coating | Uncoated |
