Arrangement for optical autocorrelation

US5581383A · kind A · utility

Assignee

• Jenoptik Technologie GmbH · DE

Inventors

• Frank Reichel · Essen, DE
• Ernst M. Gaertner · Arlington Heights, US

Key dates

• Filing date: Feb 28, 1995
• Grant date: Dec 3, 1996
• Expiry date: Feb 28, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/48
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An arrangement for optical autocorrelation of laser speckle photography (LSP) photographs or particle image velocimetry (PIV) photographs using optical Fourier transforms is disclosed. The object of providing an electro-optical arrangement for optical correlation of LSP film recordings and PIV film recordings which is simple to produce and accurate is met by using an optically addressable liquid crystal SLM (spatial light modulator) for producing the Young's fringe patterns which contains a uniaxial double-refracting liquid crystal layer and is read out with linearly polarized light of a laser light source, wherein the polarization direction of the laser light source on the readout side coincides with the extraordinary semi-axis of the refractive index ellipsoid of the liquid crystal layer.