N-BK7 Plano-Convex Lenses (High Power, V-Coated: 633 nm)

Common Specifications Lens Shape Plano-Convex Substrate Material N-BK7 (Grade A)a Coating (V-Coat) 633 nm Diameters Available 1/2" or 1" Diameter Tolerance +0.00/-0.10 mm Thickness Tolerance ±0.1 mm Focal Length Tolerance ±1% Surface Quality 20-10 Scratch-Dig Design Wavelength 587.6 nm Index of Refraction @ 633 nm 1.515 Reflectance @ 633 nm <0.25% Surface Flatness
(Plano Side) λ/2 Spherical Surface Power

b

(Convex Side) 3λ/2 Surface Irregularity
(Peak to Valley) λ/4 Abbe # vd = 64.17 Centration ≤3 arcmin Clear Aperture >90% of Diameter Focal Length Tolerance ±1%

Features

• Material: N-BK7
• AR V-Coated: 633 nm
• Ø1/2" or Ø1" Plano-Convex Spherical Singlet Lenses

These Plano-Convex Lenses are fabricated from N-BK7 glass and feature laser line V-coats at 633 nm for use with popular high-power HeNe lasers with pulsed outputs up to 10 J/cm2. N-BK7 is a common optical glass that can be used for high-quality optical components. It is typically chosen whenever the additional benefits of UV fused silica (i.e., good transmission further into the UV and a lower coefficient of thermal expansion) are not necessary.

These plano-convex lenses are popular for many applications. They have a positive focal length and near-best-form shape for infinite and finite conjugate applications. Plano-convex lenses focus a collimated beam to the back focus and collimate light from a point source.

To minimize the introduction of spherical aberration, a collimated light source should be incident on the curved surface of the lens when being focused and a point light source should be incident on the planar surface when being collimated. The focal length of each lens can be calculated using a simplified thick lens equation. f= R/(n-1), where n is the index of refraction and R is the radius of curvature of the lens surface. These lenses are fabricated from N-BK7, which has an Abbe Number of 64.17; this value is an indicator of the dispersion.

V-Coating:
V-coating is a multilayer, antireflective, dielectric, thin-film coating that achieves lower reflectance over a narrower bandwidth when used within their design AOI range. Reflectance rises rapidly on either side of this minimum, giving the reflectance curve a “V” shape (see Graphs tab for performance plots). When compared to broadband AR offerings, dielectric V-coats achieve lower reflectance over a narrower bandwidth.

With a reflectance of less than 0.25% at the coating wavelength, these lenses provide exceptionally efficient transmittance and are ideal for use with HeNe lasers, as well as applications where light is transmitted through complex optical systems. Durable and capable of withstanding up to 10 J/cm2 (10 ns, 10 Hz), these V-coated spherical singlets are also particularly well-suited for high-power applications.