SLB-20B-25PIR1 Biconvex Lens

[Features]
· With both faces convex, this lens can efficiently refract light in a restricted space, and collect large quantities of light.
· It is used to collect collimated light at as short a distance as possible or to gather as much light radiated from a light emitting point as possible.
· A BK7 lens for the visible range to the near infrared range.
· Three types of lenses with antireflection coating in the visible range, near-infrared range, and infrared range are available.
· Selection can be made from a wide range of variations subdivided by outer diameter, focal distance, and so on, to suit the specifications.
· Achromatic lens (DLB) subjected to chromatic aberration correction is also available.
· * Spherical surface biconvex lenses have chromatic aberration, resulting in focal lengths changing with wavelength.
· * Biconvex lenses have larger spherical aberration than planoconvex lenses, and as such the focal spots may not converge into one point.
· * Non-coated products have loss due to reflections at the front and rear surfaces, with a transmittance of about 90%.
[Product Specifications]
· [ Common Specifications]
· Material: BK7
· Design Wavelength: 546.1 nm
· Refractive Index: n e = 1.519
· Coating: Anti-reflective Film (633-1,064 nm)
· Transmittance: > Average 98.5%
· Laser Yield Strength (Reference Value): Anti-reflection Coating 4 J/cm^2 (Pulse Width 10 ns, Repetition Frequency 20 Hz)
· Effective diameter: 85% of the outer diameter for D ≥ φ10 mm, and 83% of the outer diameter for D < φ10 mm
· Scratch-Dig: 20-10 φ10 mm ≤ D, 40-20 D < φ10 mm
· [Individual Specifications]
· Antireflection Film Coating Wavelength Region: 633-1,064 nm
· Outer diameter φD: φ20 mm
· Focal distance f: 26 mm
· Rim thickness te: 2 mm
· Central thickness tc: 6 mm
· Back focus fb: 24 mm
· Radius of the curvature r: 25.95 mm
· Eccentricity: < 1'