A meniscus lense is an optical lense consisting of a concave and a convex surface with different radii of curvature on each side. They have the potential to have a generally advantageous outcome with the right radius of curvature. In order to lessen the focus of the beam, meniscus lenses are employed in multi-lens focusing objectives. Frequently, output couplers or variable reflectivity resonance mirror substrates have lenses with similar radii of curvature on the opposing sides.
Positive and negative meniscus lenses are the two categories into which meniscus lenses fall. Alfa Chemistry is the partner of choice for the manufacture of a wide range of custom meniscus lenses to customer specifications, with custom options with or without anti-reflection coating. Our skilled professionals test each product in our state-of-the-art metrology laboratory to ensure it meets standards. For more information on your custom meniscus lenses needs, please contact our technical sales team.
Our Capabilities
Alfa Chemistry provides high quality custom positive and negative meniscus lenses. Positive meniscus lenses have edges that are thicker than centers and are more curved on the convex side than the concave side, both of which contribute to positive focal length. Negative meniscus lenses are more curved on the concave side than on the convex side, and their center thickness is greater than their edge thickness, resulting in a negative focal length.
When combined with other lenses, positive meniscus lenses focus light to shorten the focal length and boost the numerical aperture (NA) of the current optical module. Negative meniscus lenses diffuse light and act in the opposite way to positive moon lenses to increase the focal length and decrease the NA of the optical module. Note that when using a positive meniscus lens to focus light, the convex surface should point towards the incident light source. Whereas for a negative meniscus lens, the concave side should point towards the incoming light.
Many different materials, including fused silica, N-BK7, sulfide glass, germanium, sapphire, and others, are employed to create these meniscus lenses. Custom coating options include uncoated substrates, broadband reflective reduction coatings that substantially reduce reflections over a range of wavelengths, and coatings that provide higher transmittance over a narrower range. Based on customer needs, we may also choose coatings for various transmission wavelength ranges. The general standards we provide to our clients are as follows. We can provide other lenses that meet your requirements.
| Dimension Tolerance | ±0.1 mm (Standard), ±0.05 mm (High Precision) |
| Center Thickness Tolerance | ±0.1 mm (Standard), ±0.05 mm (High Precision) |
| Paraxial Focal Length | ±2% |
| Surface Quality | 60/40 (Standard), 20/10 (High Precision) |
| Surface Figure | λ/2 (Standard), λ/4 (High Precision) @633 nm |
| Clear Aperture | >85% |
| Centration | 3 arc minutes |
| Bevel | <0.25 mm×45° |
| Material | Fused silica, N-BK7, sulfide glass, germanium, GaAs, ZnSe, BaF2/CaF2/MgF2, sapphire, etc. |
| Coating | Upon requirement |
Common Applications:
- Infrared lense assembly;
- CO2 laser focusing lense;
Quality Assurance
Each custom meniscus lense is carefully tested to all applicable standards using state-of-the-art metering equipment. We inspect and scrutinize every product before it's shipped to customers, so customers can have complete confidence that the optics they order will be the best fit for their application.
Alfa Chemistry is always looking to expand and work with customers to achieve their specifications, so please feel free to contact our technical sales team for more information and guidance on your enquiry.