87-957 25 mm Dia. Germanium Positive Meniscus Lens; EFL=35mm Uncoated
- Type
- Lens
- Subtype
- Spherical Lens (Convex-Concave)
- Brand
- Edmund Optics
Properties
- Shape
- Circular
- Diameter
- 25 mm
- EFL
- 35 mm
- BFL
- 33.29 mm
- R1
- 38.43 mm
- R2
- 57.61 mm
Material
- Name
- Germanium
- Dispersion Equation
- Sellmeier
- n (λ)
- 4.00355628065046
- λ
- 10600 nm
- B1
- 0.4886331
- C1
- 1.393959 μm2
- B2
- 14.5142535
- C2
- 0.1626427 μm2
- B3
- 0.0091224
- C3
- 752.19 μm2
87-957 25 mm Dia. Germanium Positive Meniscus Lens; EFL=35mm Uncoated
The 87-957 is a 25 mm diameter Germanium positive meniscus lens, boasting an effective focal length (EFL) of 35mm and a distinct uncoated finish. This lens, sourced from the reputable vendor Edmund Optics, is a spherical lens with a convex-concave base shape, contributing to its unique optical properties.
The lens's geometry is meticulously designed, with a thickness of 1.6mm at the edge and 2.5mm at the center. The first radius of curvature (r1) is 38.43mm, while the second radius (r2) is 57.61mm, demonstrating the lens's intricate manufacturing process. The back focal length (bfl) is 33.29mm, and both the inner and outer radii are 0mm, indicating a uniform curvature throughout the lens.
The lens is composed of germanium burnett, a material known for its high refractive index and transparency in the infrared spectrum, specifically at a wavelength of 10600nm. This makes the 87-957 particularly suitable for infrared applications.
Notably, the lens is uncoated, which means it does not have any additional layers to enhance its optical performance. While this may result in a slightly lower transmission rate and increased susceptibility to environmental factors, it also means the lens is more cost-effective and easier to clean.