Request a quote Large Plano-Concave Lenses
Precision plano-concave lenses for beam expansion and optical divergence.
Product Overview
Large plano-concave lenses have one flat surface and one concave spherical surface, providing negative optical power in air.
They diverge incident light and can serve as the negative element in a beam expander; the required aperture depends on beam size.
Material, dimensions, surface radii, focal length and coating requirements can be specified to your drawings, subject to manufacturing review.
Applications
- Laser Processing Beam Expanders: Negative input elements paired with positive lenses to increase beam diameter before downstream focusing optics.
- Optical Inspection & Metrology: Adjusting beam divergence and illumination coverage in measurement systems requiring a specified larger clear aperture.
- Projection & Illumination Equipment: Spreading source light or modifying convergence within a multi-element illumination path.
- Laser Research & Optical Testing: Introducing negative optical power to control beam vergence in larger-aperture experimental setups.
Typical Specifications
| Parameter | Standard Grade | Precision Grade |
|---|---|---|
| Materials | N-BK7, Quartz, CaF₂, MgF₂, ZnSe, ZnS, and other optical glass upon request | N-BK7, Quartz, CaF₂, MgF₂, ZnSe, ZnS, and other optical glass upon request |
| Diameter | 5–300 mm | 5–300 mm |
| Diameter Tolerance | +0 / −0.10 mm | +0 / −0.02 mm |
| Center Thickness Tolerance | ±0.10 mm | ±0.02 mm |
| Radius of Curvature Tolerance | ±0.5%–±1% | ±0.1% |
| Surface Figure | λ/4 @ 632.8 nm | λ/10 @ 632.8 nm |
| Surface Quality (Scratch–Dig) | 40–20 | 20–10 / 10–5 |
| Surface Roughness (Ra) | ≤1.0 nm | ≤0.3 nm |
| Centration Error | <3′ | <30″ |
| Angle / Wedge | 1′–5′ | 1″–10″ |
| Coating | AR / HR, etc., to customer requirements | AR / HR, etc., to customer requirements |
Other specifications, materials, and coatings are available upon request.