Triplet achromatic lenses made of fused silica(SiO2) and calcium fluoride(CaF2) materials are used to correct chromatic aberration mainly through the different dispersion characteristics of these two materials.

Fused Silica (SiO2):
Abbe number: High (about 67.8), a low dispersion material.
Refractive index: moderate (about 1.46 in the visible range).
Transparent range: good from ultraviolet to near infrared.

Calcium Fluoride (CaF2):
Abbe number: low (about 95.3), a high dispersion material.
Refractive index: low (about 1.43 in the visible range).
Transparent range: from UV to IR, especially excellent in the UV region.

What are the advantages of triplet achromatic lenses made of CaF2 and fused silica?
Wide band transmission: fused silica and CaF2 have good light transmission in the UV to IR bands, suitable for wide spectrum applications.
High chromatic aberration correction ability: the dispersion characteristics of the two materials are very different, which can effectively correct chromatic aberration.
Thermal stability: fused silica and CaF2 have low coefficient of thermal expansion and are suitable for environments with large temperature changes.

What are the applications of triplet achromatic lenses in CaF₂ and fused silica materials?
UV optical systems: such as UV microscopes and UV laser systems.
High precision optical instruments: such as astronomical telescopes and high resolution camera lenses.

Highly Recommended Optical Lenses from Yutai Optics:
UV Fused Silica Lenses
Optical Doublet Lenses
Plano Convex(PCX) Lenses
N-BASF64 / N-BK7 / N-BASF64 Triplet Lenses