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TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. Learn More

25mm Dia x 75mm FL 8-12μm Coated, Ge Aspheric Lens

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Stock #68-258 In Stock
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C$1,330.00
Qty 1-5
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C$1,064.00
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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):
72.30
Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More
Germanium (Ge)
Aspheric Design Wavelength (nm):
4000
Asphere Figure Error, RMS @ 632.8nm:
λ/6
Coating:
BBAR (8000-12000nm)
Coating Specification:
Ravg <3.0% @ 8 - 12μm
Centering (arcmin):
≤5
Surface Quality:
60-40
Clear Aperture CA (mm):
22.5
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):
78
Shape of Back Surface:
Concave
Type:
Aspheric Lens
Wavelength Range (nm):
8000 - 12000
Conjugate Distance:
Infinite

Regulatory Compliance

RoHS 2015:
Certificate of Conformance:
Reach 235:

Product Family Description

  • Diffraction Limited Performance
  • Variety of Coating Options
  • Full Prescription Data Available
  • Due to material supply chain disruptions with germanium, there may be increased lead times and price changes on our germanium products. For more information, please contact our customer service team.

TECHSPEC® Germanium Infrared (IR) Aspheric Lenses provide diffraction-limited focusing performance over a broad spectral range in the Mid and Long Wave infrared regions. Ideal for monochromatic light sources, such as quantum cascade lasers, these lenses offer a high-performance alternative to standard plano-convex lenses. 
The lenses are available in a 12.5, 25, or 50mm diameter. TECHSPEC® Germanium Infrared (IR) Aspheric Lenses are available uncoated, or with BBAR coating options. 

Uncoated germanium has transmission of <50%, so custom anti-reflection (AR) coatings should be considered if specifying an uncoated lens. Each BBAR coated lens offers >95% transmission, making it ideal for integration into a variety of OEM applications. For custom design or coating options, please contact our Sales Department.

Technical Information

AR COATED GERMANIUM

Typical transmission of a 3mm thick Ge window with BBAR (3000-5000nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg <3% @ 3000 - 5000nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick Ge window with BBAR (3000-12000nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg <5.0% @ 3 - 12μm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick Ge window with BBAR (8000-12000nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg <3.0% @ 8 - 12μm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data