Universitãt Stuttgart

Daniel Claus

Alois Herkommer

Wolfgang Osten

Christof Pruss

Klaus Koerner

Klaus Körner

Arnulf Roeseler

Arnulf Röseler

Klaus KÖRNER

The present invention relates to a method and an assembly for chromatic confocal spectral interferometery, in particular also for spectral domain OCT (SD-OCT) using multi-spectral light. A multiple (e.g. two, three, four, etc.) axial splitting of foci in the interferometric object arm is performed using a multifocal (e.g. bifocal, trifocal, quattro-focal, etc.) optical component, forming thereby at least two, three or even several groups of chromatically split foci in the depth direction. The multifocal optical component is made of a diffractive optical element () and a Schwarzschild objective (). At least two, three, four or even more differently colored foci of different groups of foci coincide in at least one confocal point in the object space of the setup. Thus, at least two, three or even more spectral wavelets are formed in the case of optical scanning of an object measurement point and spectral detection in the wavenumber domain, which wavelets are at least slightly spectrally separated from each other. This results in a significant increase in the optical primary data in the wavenumber domain and reduces the trade-off of the chromatic confocal spectral interferometry between axial measurement range and depth resolution. From the detected data, it is possible to calculate tan (alpha) as the quotient of the absolute phase shift delta_phi and the associated wavenumber difference delta_k, the Fourier transform over the spectral data, in order to respectively determine the optical path difference.

Method and assembly for chromatic confocal spectral interferometry or spectral domain oct

Disclosed herein is a measuring probe and an arrangement for measuring spectral absorption, preferably in the infrared. Furthermore, the invention relates to a method for spectroscopically measuring absorption. The measuring probe may comprise a cutting apparatus configured to cut a slice or respectively flap off of a sample to be measured; a measuring gap configured to accommodate the sample slice; an optical window element for coupling measuring light into, or respectively out of the measuring gap; and an end reflector designed and arranged to reflect the measuring light propagated through the measuring gap back into the measuring gap. The arrangement for measuring spectral absorption may comprise the measuring probe, a light source and an apparatus for the spectral analysis of the measuring light coupled out of the measuring gap.

Method and apparatus for optical absorption measurements

Disclosed herein is an apparatus for spectroscopic ellipsometry, preferably for infrared spectroscopic ellipsometry, and a method for spectroscopic ellipsometry employing the apparatus. In some embodiments, the apparatus may comprise a light source (), a detector (), a polarizer (), an analyzer (), and a measuring probe (). In one embodiment, the measuring probe may comprise an ATR prism () having at least one first surface having at least one measuring portion (M) configured to be brought in optical contact with a measured object (), and at least one second surface having at least one reflective portion (RX).

Apparatus and a method for spectroscopic ellipsometry, in particular infrared spectroscopic ellipsometry

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Stuttgart, Germany

Daniel Claus