Optical Bi-Convex (Double Convex) Glass Lenses

Bi-Convex Lenses have two symmetrically curved spherical surfaces with equal or similar radii, causing incident parallel light to converge to a real focal point. 

They provide stronger converging ability than plano-convex lenses in 1:1 imaging configurations and better balance of spherical aberration and coma in finite conjugate systems. 

Commonly made from N-BK7, fused silica, or other optical glasses, bi-convex lenses are widely used in imaging relays, beam focusing, collimation pairs, and magnification optics.

Specifications:

• Material: N-BK7, UV Fused Silica (JGS1), B270, SF series, CaF₂ (on request)
• Diameter: Ø5 mm – Ø300 mm (custom available)
• Focal Length: f = 10 mm – 2000 mm+
• Diameter Tolerance: +0.00 / −0.10 mm (or ±0.02 mm precision)
• Center Thickness Tolerance: ±0.02 mm
• Surface Quality: 60‑40 / 40‑20 / 20‑10 Scratch‑Dig
• Surface Irregularity: λ/4 or λ/10 @ 632.8 nm
• Centration (Decenter): ≤ 3 arcmin
• Clear Aperture: ≥ 85%–90% of diameter
• Edge Thickness: Controlled minimum (typically ≥ 1.0 mm)
• Coating Options: Uncoated / MgF₂ / BBAR (400–700 nm, 650–1050 nm, 1050–1650 nm) / V‑Coating