Compared with singlet lenses, Yutai's achromatic doublets are optimized to provide a focal length independent of aperture and operating wavelength and have superior off-axis performance. This is accomplished by utilizing a multielement design to minimize the chromatic aberration of the lens. Dispersion in the first (positive) element of the doublet is corrected by the second (negative) element, resulting in better broadband performance than spherical singlets or aspheric lenses. Yutai's doublets with diameter 3mm to 9mm are widely used in many analytical and medical devices.

Specifications:
Materials:two different optical glass
Diameter:3—200mm
Diameter Tolerance:+/-0.1 mm
Thickness Tolerance:+/-0.1mm
Centring Error<3 Arc minutes
Surface Quality:40/20
Surface Figure:λ/4@633nm
Clear Aperture:90%
Coating: Specified by customers