E-68-266 25mm Dia x 75mm FL 3-5μm Coated, Hybrid Ge Aspheric Lens
E-68266 25mm Dia x 75mm FL 3-5μm Coated, Hybrid Ge Aspheric Lens
Diameter (mm): 25.00 +0.0/-0.1
Effective Focal Length EFL (mm): 75.00 @ 4000nm
Numerical Aperture NA: 0.17
Back Focal Length BFL (mm): 72.79
Substrate: Germanium (Ge)
Aspheric Design Wavelength (nm): 4000
Coating: BBAR (3000-5000nm)
Coating Specification: Ravg <3.0% @ 3 - 5μm
Surface Accuracy, P-V (μm): 0.3
Centering (arcmin): ≤5
Surface Quality: 60-40
Clear Aperture CA (mm): 24.0
Edge Thickness ET (mm): 2.39
Center Thickness CT (mm): 2.80 ±0.10
f/#: 2.94
Bevel: Protective bevel as needed
Edges: Diamond Turned
Radius R2 (mm): 100.8
Shape of Back Surface: Concave
Wavelength Range (nm): 3000 - 5000
Conjugate Distance: Infinite
Asphere Figure Error, RMS @ 632.8nm: λ/6
Product Family Description
- Color Corrected for 3 – 5μm
- Near Diffraction Limited Focusing Performance
- Full Prescription Data Available
Our TECHSPEC® Germanium Infrared (IR) Hybrid Aspheric Lenses provide diffraction limited focusing performance at any wavelength in the 3 – 5μm region, and near diffraction limited performance when used over the entire 3 -5μm spectral range. They are ideal for integration into imaging applications, FTIR spectrometers, or any Mid-Wave IR application utilizing a broad band light source.
Each hybrid aspheric lens is coated for >95% transmission for the most efficient use of costly infrared illumination. However, transmission is limited by the inherent diffraction efficiency of the aspheric surface, yielding lower overall transmission at the extremes of the design spectral band.