67-998 20mm Dia. x -50 FL; NIR II Coated; Plano-Concave Lens 750-1550nm
- Type
- Lens
- Subtype
- Spherical Lens (Plano-Concave)
- Brand
- Edmund Optics
Properties
- Shape
- Circular
- Diameter
- 20 mm
- EFL
- -50 mm
- BFL
- -52.31 mm
- R1
- -25.84 mm
Material
- Name
- N-BK7
- Dispersion Equation
- Sellmeier
- n (λ)
- 1.5167984379050088
- λ
- 587.6 nm
- B1
- 1.03961212
- C1
- 0.00600069867 μm2
- B2
- 0.231792344
- C2
- 0.0200179144 μm2
- B3
- 1.01046945
- C3
- 103.560653 μm2
67-998 20mm Dia. x -50 FL; NIR II Coated; Plano-Concave Lens 750-1550nm
The 67-998 is a 20mm diameter Plano-Concave lens with a focal length of -50, sourced from Edmund Optics. This lens is designed for use in the near-infrared (NIR) spectrum, specifically between 750 and 1550nm, as indicated by its NIR II coating.
The lens's geometry is characterized by a diameter of 20mm, a thickness at the edge of 5.21mm, and a center thickness of 3.5mm. The front surface has a radius of curvature (R1) of -25.84mm, and the back focal length (BFL) is -52.31mm. The lens is made of N-BK7 Schott glass, a common material for optical elements due to its excellent optical properties and availability.
The lens's coating is a standard curve from Edmund Optics' NIR II series, applied to both the front and back surfaces. This coating enhances the lens's performance in the NIR spectrum by reducing reflection and increasing transmission.