A double convex lens is a spherical lens with both surfaces convex, featuring a center thickness greater than the edge thickness. It converges light, focusing parallel rays to a point or transforming a point light source into a parallel beam. As one of the most fundamental and widely used optical imaging and focusing components, it is extensively applied in imaging, laser collimation, illumination, medical, and educational fields.

Key Parameters and Features

1. Diverse Materials: BK7, fused silica (JGS1), sapphire, CaF?, silicon, germanium, etc., covering wavelengths from visible to far-infrared.

2. Focal Length Range: Available from a few millimeters to several thousand millimeters, with standard tolerance ±2% and customizable ±0.5%.

3. Surface Accuracy: λ/4 to λ/10 (@633 nm), surface roughness RMS <10 ?, ensuring low scattering and low wavefront distortion.

4. Clear Aperture: Over 90% of the diameter, with optional anti-reflection (AR), high-reflection (HR), or partial-reflection (PR) coatings.

5. Laser Damage Threshold: Fused silica material with high-threshold coatings can withstand >10 J/cm2 (1064 nm, 10 ns, 10 Hz) laser energy.

6. Standard Outer Diameter: Φ4 mm – Φ200 mm, center thickness tolerance ±0.1 mm, edge bevel 0.2–0.5 mm×45°, facilitating safe assembly.