Method and apparatus for comparing optical properties of two liquids

US11340162B2 · kind B2 · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Thomas Burg · Cambridge, US
• Margherita Bassu · Oettingen, DE
• Foelke Purr · Braunschweig, DE
• Andreas Heinrich Dietzel · Wallertheim, DE

Key dates

• Filing date: Apr 16, 2020
• Grant date: May 24, 2022
• Expiry date: Aug 28, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/4153
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

For comparing first optical properties of a first fluid with second optical properties of a second fluid a first transparent grating having a grating constant is made of the first liquid, and a second transparent grating also having the grating constant is made of the second liquid. The second transparent grating is arranged at a lateral offset of less than 45% of the grating constant with regard to the first transparent grating such that grating bars of the first and second transparent gratings are arranged side by side. Coherent light is directed onto the first and second transparent gratings such that light which passed through the grating bars of the first and second transparent gratings forms a diffraction pattern comprising intensity maxima. Two light intensities of two intensity maxima of a same order higher than zero are measured and compared to each other.