Method and assembly for confocal, chromatic, interferometric and spectroscopic scanning of optical, multi-layer data memories

US7876446B2 · kind B2 · utility

Assignee

• UNIVERSITAT STUTTGART · DE

Inventors

• Klaus Körner · Berlin, DE
• Reinhard Berger · Bühl, DE
• Ulrich Droste · Berlin, DE
• Christian Kohler · Dresden, DE
• Wolfgang Osten · Lilienthal, DE
• Christof Pruss · Scharnhauser Park, DE
• Aiko Ruprecht · Wedel, DE
• Tobias Wiesendanger · Wiesloch, DE

Key dates

• Filing date: Feb 3, 2006
• Grant date: Jan 25, 2011
• Expiry date: Jul 7, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G11B2007/0013
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

An interferometric confocal method and assembly for terabyte volume optical data memories couples two-beam spectral interferometry to chromatic confocal technology and permits a longitudinal splitting of foci in the memory volume, with the foci having limited diffraction. A spectrometer is located downstream of the interferometer with confocal discrimination in the beam path. A diffractive optical zone lens (DOZE) with a usage of the first diffraction order is introduced into the interferometric beam path to achieve longitudinal chromatic splitting. The interferometer can be a fiber-coupled interferometer with a retroreflector in the fiber-coupled reference arm and with wavelength-dependent optical path difference modification by dispersion or diffraction. The optical path difference in the interferometer is set so that easily detectable wavelets are formed from detectable interferograms by spectral analysis.