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

US11248900B2 · kind B2 · utility

Assignee

• UNIVERSITAT STUTTGART · DE

Inventors

• Klaus Körner · Berlin, DE
• Daniel Claus · Stuttgart, DE
• Alois Herkommer · Aalen, DE
• Christof Pruss · Scharnhauser Park, DE

Key dates

• Filing date: Dec 18, 2017
• Grant date: Feb 15, 2022
• Expiry date: Dec 18, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2210/50
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

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 (712) and a Schwarzschild objective (5). 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 be…