Patent ID: 9651364
Date: 2017-05-16
CPC Classifications: G01B,G01H

Claim:
1. A method for laser-optical detection of a surface movement of a sample, the method comprising: obtaining a first reference beam and a first measurement beam from a laser beam, directing the first measurement beam onto the sample to reflect the first measurement beam, superimposing the first reference beam with the first measurement beam reflected by the sample in a first photorefractive/electro-optical element, converting the light emerging from the first photorefractive/electro-optical element into a first electric signal and then evaluating the first electric signal, superimposing a second reference beam obtained from the first reference beam with a second measurement beam obtained from the reflected first measurement beam in a second photorefractive/electro-optical element, converting the light emerging from the second photorefractive/electro-optical element into a second electric signal, subtracting the second electric signal from the first electric signal prior to evaluating the first electric signal, and applying mutually inverse voltages to the first and second photorefactive/electro-optical elements.