Description
Ø3mm Molded Glass Aspheric Collimating Lenses — L-BAL35, for Miniature Laser Diode Modules
Our Ø3 mm aspherical collimating lenses are precision-molded from OHARA L-BAL35 low-dispersion optical glass, offering superior spherical aberration correction compared to spherical singlets for compact laser diode collimation.
Available in standard EFLs from 1.8 mm to 6.2 mm and with BBAR coatings for UV-VIS (405 nm) through NIR (1064 nm), these unmounted aspheric singlets are the core optical element for M6/M9 threaded collimator barrels, pen-type pointers, and custom OEM LD packaging.
Custom aspheric sag/profile, EFL, diameter (down to Ø1.5 mm), and coating bands available on request.
Specifications:
Material: OHARA L-BAL35 Optical Glass (nd = 1.58913 @ 587.6 nm; νd = 61.17; similar to N-BK7 in index)
Diameter (Ø): 3.0 mm (±0.02 mm typical)
Profile: Aspherical — convex aspheric surface + plano back (Plano-Convex Asphere)
Effective Focal Length (EFL): Commonly 1.8 / 2.0 / 2.5 / 3.0 / 4.05 / 6.2 mm (custom per drawing; typical for LD collimation: 2.0–4.05 mm)
Center Thickness: 1.0 – 2.0 mm (depends on EFL)
Aspheric Conic / Polynomial: Per Zemax / Code V prescription (provided on request)
Surface Quality: 60-40 / 40-20 Scratch-Dig (premium 20-10 on request)
Surface Roughness (RMS): < 20 nm (molded & polished)
Clear Aperture: ≥ 85% of diameter (≈ Ø2.55 mm)
Coating Options:
— Uncoated
— MgF₂ (single layer)
— BBAR @ 405–450 nm / 515–550 nm / 630–680 nm / 700–1100 nm / 400–700 nm
— Dual-wavelength or V-coating on request
Operating Temp: −40 °C ~ +80 °C
Typical NA Match: 0.25 – 0.45 (matches 5.6 mm TO-can LD fast axis)
For Collimating lens, the focal length we have 3.77mm,4.02mm, 4.39mm,6mm,6.2mm ,6.5mm,8mm, 8.3mm, 9.8mm, 10mm,11.2mm and 12mm.
Check the stock lenses in the following files.
