2 mm Cemented Triplet Lens / Three-Element Achromatic Lens
Specifications
Lens Type: Achromatic Triplet Lens (Cemented 3-Element – Steinheil or Hastings design)
Outer Diameter (OD): 2.00 mm (+0.000 / –0.025 mm)
Effective Focal Length (EFL): 4.0 / 6.0 / 8.0 / 10.0 mm standard (custom EFL on request)
Back Focal Length (BFL): Per design (typically 60–80% of EFL)
Center Thickness (Total): 1.2 – 2.5 mm (design dependent)
Clear Aperture: > 1.6 mm (> 80% of OD)
Glass Combination Examples: N-BK7 + N-SF6 + N-SF6 (Steinheil); N-SF2 + N-BK7 + N-SF2 (Hastings); N-PSK53A + N-SF57 + N-SF57 (enhanced apochromat-like)
Surface Quality: 20-10 or 40-20 Scratch-Dig (MIL-PRF-13830B)
Surface Irregularity: λ/4 @ 632.8 nm (λ/8–λ/10 optional)
Centration Error: ≤ 3 arcmin (≤ 1 arcmin available)
Cement: UV-curing optical epoxy (low shrinkage, high transmission 350–2000 nm)
Coating Options: Uncoated / MgF₂ single-layer / BBAR 400–700 nm (Ravg < 0.5%) / BBAR 650–1050 nm on both air-glass surfaces
Wavelength Range: 420–680 nm (VIS standard); 340–900 nm (extended on UVFS combos)
Operating Temp: –20°C to +80°C (std epoxy); +150°C (high temp air-spaced option)
Bevel / Chamfer: Protective bevel 0.03–0.08 mm × 45°
