S-SLB-30-200NIR1 Concave Lens

[Features]
· A product with surface quality one level below the spherical concave lens (SLB-N).
· Use for optical systems that do not require high surface quality, such as for lighting or observation.
· Specifications other than the surface quality are almost the same as the spherical concave lens (SLB-N).
· With the exception of high-precision experiments using lasers, we recommend this lens.
· A plano-concave lens with little spherical aberration and a bi-concave lens that can greatly refract and shorten the focal length are available.
· In addition to the non-coated product, three types of lenses with anti-reflective coating for the visible range, near-infrared range, and infrared range are available.
· * Spherical surface biconcave lenses have chromatic aberration, resulting in focal lengths changing with wavelength.
· * Non-coated products have loss due to reflections at the front and rear surfaces, with a transmittance of about 90%.
· * The outer ridgeline of the concave surface is chamfered.
· * As such, the edge thickness (te) may be smaller than designed.
[Product Specifications]
· [ Common Specifications]
· Material: BK7
· Design Wavelength: 546.1 nm
· Refractive Index: n e = 1.519
· Eccentricity: < 3'
· Coating: Anti-reflective Film (633-1,064 nm)
· Transmittance: > Average 98.5%
· Laser Yield Strength (Reference Value): 4 J/cm^2 (Pulse Width 10 ns, Repetition Frequency 20 Hz)
· Effective Diameter: 85% of External Diameter
· Scratch-Dig: 60-40
· [Individual Specifications]
· Antireflection Film Coating Wavelength Region: 633-1,064 nm
· Outer diameter φD: φ30 mm
· Focal distance f: -200 mm
· Rim thickness te: 3.1 mm
· Central thickness tc: 2 mm
· Back focus fb: -201.3 mm
· Radius of the curvature r: 103.8 mm