25mm diameter focal length 20mm glass aspherical lens optical lens zoom lens optical element

25mm diameter focal length 20mm glass aspherical lens optical lens zoom lens optical element

Optical Aspherical Lens

25mm diameter aspherical lens

custom 25mm aspherical glass lens

factory offer optical aspheric lens

High-precision optical glass aspherical lens with 25mm clear aperture and 20mm effective focal length (f/0.8), designed to replace multi-element spherical lens groups by eliminating spherical aberration and improving spot quality.

Molded or polished from N-BK7 or low-dispersion crown glass, with optional broadband AR coating for visible or VIS-NIR bands. Suitable for compact zoom lens assemblies, condenser systems, collimators, and high-NA imaging optics. Acts as a primary focusing element in zoom or varifocal optical trains.

Custom NA, conjugate distances, and coating wavelengths available for OEM lens modules.

Description

Specifications:

Lens Type: Optical Glass Aspherical Singlet Lens (Molded / Ground & Polished)

Material: N-BK7 (nd=1.5168, νd=64.2) / K9 (H-K9L) / H-LaK Series / Custom Low-Dispersion Glass

Diameter (Clear Aperture): 25mm (Ø25mm)

Effective Focal Length (EFL): 20mm (Custom 15–100mm available)

Back Focal Length (BFL): Specified per design (typically ~17–19mm for EFL=20mm)

Numerical Aperture (NA): ~0.56 (f/0.8 relative to clear aperture)

Center Thickness: 4mm – 10mm (design dependent)

Dimension Tolerance: ±0.05mm / ±0.1mm

Center Thickness Tolerance: ±0.05mm

Surface Figure (Base Sphere): λ/4 @ 632.8nm

Surface Roughness (RMS): <20nm (Molded) / <5nm (Polished)

Surface Quality (Scratch-Dig): 60-40 / 40-20 / 20-10

Clear Aperture: ≥90% of Ø25mm

Edge Treatment: Ground / Edge Blackened (Optional) / Bevel 0.2–0.5mm × 45°

Aspheric Coefficients: Optimized per wavelength band (available on request)

Coating Options:

Uncoated
MgF₂ AR @ 550nm
Broadband AR 400–700nm (Ravg<0.5%)
Broadband AR 600–1050nm (VIS-NIR)
V-Coating @ 532nm / 635nm / 850nm / 1064nm / Custom

Operating Wavelength: 400–700nm (Standard VIS), 350–2200nm (Substrate Dependent)

Transmission: >99% per surface with AR coating

Operating Temperature: -40°C to +80°C

We are professional manufacture on the optical lenses &lasers for over 20 years experience.
With the advanteges,we offer optical products in the fileds of University laboratory, Industry, Scientific research,Medical treatment, Mechanical equipments, lasers and Construction industry and so on.

We can provide optical lenses, optical prisms, high-precision Powell prisms, right-angle prisms, laser lenses, filters, aspherical lenses, collimating lenses, optical glass lenses, optical reflectors, cylindrical lenses, laser modules, laser heads, optical glued lenses, optical rod mirrors, etc.

Looking forward to communicating whether we have the opportunity to cooperate. For the lens/laser products you need, I would like to quote our competitive price.

Please contact for any custom needs,
Contact:Rebecca Xu