DL-25-50NM Lens

[Features]
· An achromatic lens with a negative focal length.
· With a single concave lens made by adhering two lenses of different wavelength dispersing refractive indices, the chromatic and spherical aberration can be reduced compared to single spherical lenses.
· Optimized for low deviation of the focal length and minimized aberration over the entire visible light range.
· It can be combined with an achromatic lens with positive focal distance to create a Galilean type beam expander.
· Corrected not only for aberrations on the on-axis object point but also for off-axis coma aberration and astigmatism.
· * Achromatic lenses are oriented for incidence of parallel light.
· * Have parallel light incident from the surface with the smaller radius of curvature (the surface indicated by the arrow).
· * Having parallel light incident from the opposite side causes chromatic and spherical aberration, and enlarges the condensing spot.
· * Chromatic aberration may increase when used with wavelengths outside the visible range.
· * Also, transmittance may be negatively affected.
[Product Specifications]
· [ Common Specifications]
· Material: N-BAF10/N-SF10
· Design Wavelength: 486.1 nm, 546.1 nm, 656.3 nm
· Coating: Anti-reflective Film
· Adhesive: UV Curable Adhesive
· Laser Yield Strength: 0.3 J/cm2
· Scratch-Dig: 40-20
· Effective Diameter: 90% of External Diameter
· [Individual Specifications]
· Outer diameter φD: φ25 mm
· Focal distance f: -49.94 mm
· Central thickness tc: 6.7 mm
· Rim thickness te: 9.3 mm
· Back focus: -53.09 mm
· Eccentricity: < 3'