Korth Kristalle GmbH

Refractive Index

1:Goniometer | 2-3: Interferometer | 4: Visual Inspection

Quality can be verified – and we don’t just test our own products.

After decades spent manufacturing the most advanced optical components from our own crystals we demand the best. Using our top of the range equipment we can assess and test your products using the same high standards we apply to our own.

Our long standing experience in this area means we know what counts and we are happy to share our know-how: we can measure, check and certify your components, materials and samples:

Transmission spectroscopy 120 nm - 25 μm on plane parallel samples up to 100 mm thickness
Stress induced birefringence Birefringence, or double refraction, is the decomposition of a ray of light into two rays when it passes through certain anisotropic materials. Isotropic solids do not exhibit birefringence unless under mechanical stress, either due to stress applied externally or as part of the manufacturing process. Mechanical stress affects the optical properties of certain materials which is undesirable in many applications (e.g. lenses for polarizing optics).  The ability to understand and quantify residual stress and its effect on optical components is therefore essential in controlling the parameters of crystal growth and optimising quality. on plane parallel samples up to 200 mm diameter
Surface roughness on polished samples up to max. 100mm hight
Wavefront distortion Where a homogenous light beam consisting of many light waves passes through an inhomogeneous material with a varying refractive index n (density variations in the material) or of non-uniform thickness, the individual light waves will be distorted proportionally to the distance travelled through the material, resulting in a deterioration of the optical image. This can be measured by analyzing the interference patterns in a two-arm or phase-shifting interferometer, where one “arm” contains the material to be measured and the other a reference sample.  on plane parallel samples up to 100 mm diameter
Centring error on lenses and parallel windows

Fluorescence Spectroscopy is a collective term used to describe methods to analyse the radiative energy of samples by dispersing their radiative energy by wavelength. Spectroscopes are used for the visual inspection of optical spectra.  Spectrometers are recording devices and are also used for other ranges of the electro-magnetic spectrum as well as particles like electrons and ions. Samples can be irradiated resulting in different emissions which can then be analysed. The oldest spectroscopic methods (called classical spectroscopy) involve the study of light emission and absorption by molecules and atoms using grating and prism spectrometers. Molecular spectroscopy studies the interaction of molecules with electro-magnetic fields. It allows for the identification of molecular properties such as bonding length and strength and the identification of atomic fragments. Molecular spectra differ from atomic spectra by many more, often overlapping lines or bands. The reason for this is that molecules not only absorb or emit energy by electron transfers but also by vibrations of atoms against one another and molecular rotation around one of their axis. on selected material (excitation source: Xe-Light)
X-ray Orientation Crystal orientation is the classification of the inclination of the crystal surface in relation to its crystal lattice. Crystal orientation is usually denoted by the Miller indices, e.g. (111) or (110) (and directions parallel or perpendicular to it). The Miller index can only be used for single crystals, i.e. not just a solid but a homogenous uniformly oriented solid. Orientated crystals are used in the semiconductor industry or in fundamental physics. Specific crystal orientation can be achieved by cleavage (see material properties) or by directional cutting.  on selected material

If you are interested in using our Testing Service please write us an Email info@korth.de or call us for a quote.