Biconcave Lens 50mm Diameter −69.5mm Focal Length 750 - 1550nm

SLB-50B-70NIR2

These biconcave lenses are used when a very high negative power is required. They can be used in a multi-element system or alone to produce a diverging cone or virtual image. Sharpe edges, which are common in negative lenses, are removed by beveling to reduce the likelihood of chipping.
◦There are two types of biconvex lenses available; BK7 for use in visible range to infrared wavelength range.
◦Our lenses are listed by outside diameter and focal length to assist your selection according to required specifications.
More Information
Name Biconcave Lens 50mm Diameter −69.5mm Focal Length 750 - 1550nm
Weight 0.0500kgs
Standard Coatings Available No
Guide
  • Lenses are available in a large selection and in custom sizes and focal lengths.
  • In addition to our standard coating we offer custom anti-reflective coating at specific wavelengths.
Remark -
Attention
  • When a concave lens is used in combination with a convex lens it will be able to converge the light and can projected a suitable image.
  • The biconvex spherical lens has chromatic aberration, and the focal length will vary depending on the wavelength. Please check the “wavelength characteristic of the focal length data” on “Technical Data” for the focal lengths of each wavelength.
  • Transmissions losses due to reflection off the front and rear surfaces of the lens can be minimized by coating the surfaces. Consult our Sales Team for anti-reflection coatings suitable for your application.
  • The outer edge of the concave side is chamfered and the result is possibility that the lens may have a smaller edge thickness for this design.
Diameter φD 50mm
Focal length −69.5mm
Material BK7
Design Wavelength 546.1nm
Refractive index n<sub>e</sub> 1.519
Coating Broadband Multilayer antireflection coating (750 - 1550nm)
Transmmittance > Average 98.5%
Laser Damage Threshold 4J/cm2 (Laser pulse width ; 10ns , Repetition frequency ; 20Hz)
Clear aperture 85% of the diameter
Surface Quality (Scratch-Dig) 20-10
Wavelength range of Antireflection Coating 750 - 1550nm
Diameter φD φ50mm
Focal length f −69.5mm
Edge thickness te 11.9mm
Center thickness tc 3mm
Back focal length fb −70.5mm
Radius of curvature r 72.66mm
Centration <1′
In stock
SKU
SLB-50B-70NIR2
$148.00

Delivery in : 2 weeks

These biconcave lenses are used when a very high negative power is required. They can be used in a multi-element system or alone to produce a diverging cone or virtual image. Sharpe edges, which are common in negative lenses, are removed by beveling to reduce the likelihood of chipping.

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