An achromatic lens

An achromatic lens is a lens designed to minimize chromatic aberration and spherical aberration. Two-plate achromatic lens is one of the simplest achromatic lenses, which can be divided into two types: double agglutination and double dissociation. Of course, achromatic lenses can also be composed of multiple lenses, depending on their uses.
Spherical doublet lenses have been corrected for various aberrations, including spherical aberration, chromatic aberration, and coma. One way of displaying the theoretical level of correction is through plots of wavefront error and ray traces to determine spot size.
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Material: BK7 ,Fused silica, sapphire
Coating: as required
Structure: round
Surface Quality: 20/10,40/20, 60/40
Diameter: 0.5mm~20mm
Clear Aperture Over : 90%
Tolerance of FL : ±2%
Surface quality : N<3(0.5)@632.8nm