Achromatic doublets are cemented achromats made of two different lenses (Low dispersion positive from crown glass and high dispersion negative from flint glass). The difference of dispersion and shape of both lenses are designed to minimize the chromatic aberrations in blue (486.1nm), green (546.1nm) and red (656.3nm). Therefore, these lenses are able to support the entire visible wavelength spectrum.
◦The spherical aberration of achromatic doublets is better than singlets and minimized at infinite conjugate ratios. ◦Achromatic Doublets are coated on both surfaces with a broadband multi-layer anti-reflection coating for the visible wavelength (400 − 700nm). ◦Set the positive part to the side of the incident parallel beam and put the negative part to the side of the focal point to minimize spherical aberration. ◦The difference in focal length of a lens at each wave length is Chromatic aberration and is due to “dispersion of the glass”, the change in refractive index of glass according to wavelength. This can be corrected by combining glasses with low and high dispersions. Spherical aberration is when a ray enters a lens farther from its optical axis and has a shorter focus than a paraxial focus.
Please contact our Sales Division for customized achromatic doublets. (Customized on size etc.)
Please refer to “Lens design data” on “Technical Data” for the lens design data.
Air spaced focusing lenses are also available (NYTL/NYDL) designed for laser processing applications.
WEB Reference Catalog Code/W3079
Remark
-
Attention
Set the positive part to the side of the incident parallel beam and put the negative part to the side of the focal point to minimize spherical aberration.
The difference in focal length of a lens at each wave length is Chromatic aberration and is due to “dispersion of the glass”, the change in refractive index of glass according to wavelength. This can be corrected by combining glasses with low and high dispersions.
Spherical aberration is when a ray enters a lens farther from its optical axis and has a shorter focus than a paraxial focus.
Be sure to wear laser safety goggles when checking optical path and adjusting optical axis.
Achromatic doublets are cemented achromats made of two different lenses (Low dispersion positive from crown glass and high dispersion negative from flint glass). The difference of dispersion and shape of both lenses are designed to minimize the chromatic aberrations in blue (486.1nm), green (546.1nm) and red (656.3nm). Therefore, these lenses are able to support the entire visible wavelength spectrum.