Technical Information

An achromat with a positive refractive power consists of a convex crown glass lens with low dispersion (color splitting) and a concave flint glass lens with a high dispersion.

The lenses are matched such that the variation of the focus position of the overall system is minimized for two selected wavelengths. A modern chromatic (color) correction of the focus position is calculated for the Fraunhofer lines C’ (479.9914 nm) and F’ (643.8469 nm). The remaining variation of the focus position (secondary spectrum), e.g. to the e-line (546.074 nm), is typically below 0.1% of the focal length.

In addition, the spherical aberration can be minimized by suitable geometry and material selections. LINOS achromats are especially well corrected against spherical aberration and are therefore very good for monochrome applications for optimum focusing and/or collimating with minimum wave front deformation, e.g. of laser light.

The modulation transfer function (MTF) illustrates the high imaging quality. This type of graph shows the resolution capacity in dependence of the resolution of the object or image structure (also see the chapter "Technical Information on Optics ". The resolution is usually close to the theoretical diffraction limit.

LINOS achromats are available with two different coatings. 

Both coatings are hard and scratchproof anti-reflex coatings.

Besides the ARB2 VIS for the visible spectral range, the selection of all microbench-compatible elements was supplemented with the ARB2 NIR for applications in the near infrared spectrum.

Please refer to the transmission diagrams for the characteristics of both coatings. One outstanding feature of both coatings is the high transmission of our achromats, which is >99% for the stated wavelength range.