N-BK7 Negative Meniscus Lens
- Negative meniscus lens has negative focal length.
- These lenses can diverge light to form virtual images.
- Suitable for beam diverging application.
- These lenses decrease NA (Numerical Aperture) when introduced in an optical system.
- N-BK7 lenses are general purpose and low cost lenses.
Application Notes
- Negative Meniscus for Imaging : When a negative meniscus lens is combined with another lens, the focal length is increased and the numerical aperture of the system is decreased.
- Negative Meniscus for Beam Diverging : Negative meniscus lens exhibit minimal spherical aberrations when diverging a (infinite conjugate) collimated beam, with convex side facing collimated beam.
- Negative Meniscus uses : Negative meniscus lens are used mostly in beam-expanding applications where minimal spherical aberrations are needed and wherever focal Length increment with NA decrement is needed.
Specification
- Material : N-BK7
- Focal length : ±1%.
- Diameter available : Ø5 to Ø100.
- Diameter Tolerance : +0/-0.1 mm.
- Clear aperture : 90%.
- Center Thickness : ±0.1mm.
- Centeration : Better than 3 arc min.
- Surface Irregularity : Lambda/4 @ 632.8 nm.
- Surface quality : 40-20 Scratch-Dig.
- Design Wavelength : 587.6 nm.
- Wavelength range : 350 nm- 2 µm. (Un-Coated)
- AR Coatings available : A)BBARC ; B) Laser V-Coating.
2. For good performance under low light conditions, we suggest you to use AR-coating from our coating catalogue.
3. Customized Designs are available from diameters of 3 mm to 300 mm with your specifications and coating options.
Product Matrix
N-BK7 Negative Meniscus Lens- Diameter 25 mm
| Quantity | Doc | Part Number | Diameter (mm) | Focal Length (mm) | Back Focal Length (mm) | Center Thickness (mm) | Edge Thickness (mm) | |
|---|---|---|---|---|---|---|---|---|
| NM-25-100 | 25 | -100 | -98.6 | 4 | 5.6 | |||
| NM-25-125 | 25 | -125 | -122.6 | 4 | 5.3 | |||
| NM-25-150 | 25 | -150 | -147.8 | 4 | 5.1 | |||
| NM-25-200 | 25 | -200 | -198.4 | 4 | 4.8 |