N-BK7 Biconcave Lenses
Negative Focal Length: The double concave lens has a negative focal length, which allows it to diverge collimated light beams to the virtual focal point.
Versatile Applications: Biconcave lenses are versatile and can be used for divergence of collimated or focused light beams, beam diameter modulation, correction of spherical aberration in optical assemblies, and increasing the focal lengths of a lens group.
Optimal Performance: Due to its symmetric structure, the double concave lens works best when the conjugate ratio is close or equal to 1:1, providing minimal distortion, spherical/chromatic aberration, and coma.
Cost-Effective: N-BK7 glass is known for its low cost, making it an economical choice for manufacturing optical components.
High Optical Transmission: N-BK7 glass offers high optical transmission across the visible spectrum and into the near-infrared region (350-2200nm).
Durability: The material is known for its high hardness and resistance to scratches and abrasions, as well as its ability to withstand changes in temperature without significant expansion or contraction.
Applications: Beam Divergence, Beam Diameter Modulation, Spherical Aberration Correction, Focal Length Adjustment, Custom Optical Solutions, etc.
Kingwin Optics offers high-quality Off-the-shelf N-BK7 Double Concave Lenses. These lenses are designed with precision and feature two identical inward-bent spherical surfaces with equal radii of curvature, making them ideal for various optical applications.
Specifications:
| Type | Biconcave Lenses |
| Diameter Tolerance | +0.00/-0.1mm |
| Clear Aperture | >90% |
| Surface Irregularity | λ/4-λ @ 633 nm |
| Thickness Tolerance | ±0.1mm |
| Focal Length Tolerance | +/-1% |
| Centering Error | 3 arcmin |
| Chamfer | 0.2mm x 45 degree |
| Material | N-BK7(H-K9L) or UV Fused Silica(JGS1) |
Features:
- Negative Focal Length: The double concave lens has a negative focal length, which allows it to diverge collimated light beams to the virtual focal point.
- Versatile Applications: Biconcave lenses are versatile and can be used for divergence of collimated or focused light beams, beam diameter modulation, correction of spherical aberration in optical assemblies, and increasing the focal lengths of a lens group.
- Optimal Performance: Due to its symmetric structure, the double concave lens works best when the conjugate ratio is close or equal to 1:1, providing minimal distortion, spherical/chromatic aberration, and coma.
- Cost-Effective: N-BK7 glass is known for its low cost, making it an economical choice for manufacturing optical components.
- High Optical Transmission: N-BK7 glass offers high optical transmission across the visible spectrum and into the near-infrared region (350-2200nm).
- Durability: The material is known for its high hardness and resistance to scratches and abrasions, as well as its ability to withstand changes in temperature without significant expansion or contraction.
Applications:
- Beam Divergence: Biconcave lenses are commonly used to diverge collimated or focused light beams in optical systems.
- Beam Diameter Modulation: They are used in Galilean beam expanders to modulate the diameter of light beams.
- Spherical Aberration Correction: Biconcave lenses are used to correct spherical aberration in optical assemblies, enhancing the overall performance of the system.
- Focal Length Adjustment: They can be used to increase the focal lengths of a lens group, allowing for more flexibility in optical design.
- Custom Optical Solutions: Kingwin Optics also provides custom biconcave lenses made from various optical materials such as BaF2, CaF2, MgF2, Ge, ZnSe, Sapphire, and others, catering to specific application requirements.
Kingwin Optics’ Off-the-shelf N-BK7 Double Concave Lenses are precision-made optical lenses with two identical inward-bent spherical surfaces and equal radii of curvature. These lenses have a negative focal length and diverge collimated light beams to the virtual focal point. The symmetric structure of the double concave lens ensures optimal performance when the conjugate ratio is close or equal to 1:1, minimizing distortion, spherical/chromatic aberration, and coma.
N-BK7 is a popular optical glass material known for its low cost, high optical transmission across the visible spectrum and into the near-infrared region (350-2200nm), low dispersion, high hardness, resistance to scratches and abrasions, and the ability to withstand temperature changes without significant expansion or contraction. Kingwin Optics offers four standard coating options for their N-BK7 Bi-concave Lenses: uncoated, 350-650nm, 650-1100nm, and 1050-1580nm broadband anti-reflection (BBAR) coatings. Custom V-coatings and low-cost MgF2 AR coatings with various transmission wavelengths can also be applied to the N-BK7 and UVFS biconcave lenses upon request. In addition to the stocked N-BK7 and UV Fused Silica Biconcave lenses, Kingwin Optics also provides off-the-shelf UV Fused Silica biconcave lenses and custom biconcave lenses made from a range of optical materials.
