Double Convex Lenses
Biconvex / Double Convex Lenses
Double convex lenses feature two outward-curving surfaces that converge parallel light rays to a focal point. These symmetric lenses excel in imaging systems, laser applications, and telecommunications where object and image distances are comparable. Avantier manufactures custom double convex lenses from optical glass, fused silica, sapphire, and infrared materials, with anti-reflective coatings optimized for your wavelength range.
When to Choose Double Convex Lenses
Double convex lenses perform best when conjugate ratios (object-to-image distance relationship) fall between 0.2 and 5. At a 1:1 ratio, these lenses minimize spherical aberration, chromatic aberration, and distortion. Their symmetric design distributes optical power evenly, making them ideal for relay systems, beam expanders, and applications where light approaches from both sides at similar angles.
Technical Specifications
The three defining parameters are substrate material, focal length, and radius of curvature. Material choice governs refractive index and transmission characteristics. Focal length determines magnification and working distance. The two convex surfaces feature equal curvature radii with opposite signs, creating the symmetric profile that defines optical behavior.
Avantier manufactures double convex lenses in BK7, K9, fused silica, sapphire, CaF2, ZnSe, and germanium. Each lens undergoes precision polishing to 40-20 scratch-dig or better, with ground and beveled edges.
Specifications
| Parameter | Specification |
|---|---|
| Material | Optical glass, fused silica, sapphire, CaF2, ZnSe, germanium |
| Diameter | 2 mm – 300 mm |
| Diameter Tolerance | ±0.05 mm (≤50 mm), ±0.1 mm (>50 mm) |
| Focal Length | 50 mm – 2000 mm |
| Focal Length Tolerance | ±0.2% (<10 mm), ±0.5% (10 – 1000 mm), ±1% (>1000 mm) |
| Surface Quality | 60/40, 40/20 |
| Surface Accuracy | λ/2 to λ/10 @ 632.8 nm, 532 nm |
| Centration | <3 arc min to 30 arc sec |
| Coating | Custom AR coatings per specification |
Key Applications
Our double convex lenses serve critical roles in microscopy and telescopes, where they relay images between optical planes. In laser systems, they focus and steer high-energy beams with precision. Telecommunications systems use them to manipulate light signals in fiber optics and free-space communication. For infrared applications—thermal imaging, remote sensing, and FTIR spectroscopy—we offer lenses in germanium and zinc selenide substrates.
Custom Manufacturing
Beyond our standard catalog, we manufacture custom double convex lenses for specialized applications. Our metrology equipment verifies focal length accuracy (±3%), centration (<1 arc minute), and surface quality before delivery. Every lens includes inspection reports and Certificates of Conformance.
