METHOD AND DEVICE FOR LASER-OPTICAL DETECTION OF A SURFACE MOVEMENT OF A SAMPLE

摘要

A method for laser-optical detection of a surface movement of a sample (1) is specified, whereby a first laser reference beam (10) is superimposed with a first laser measurement beam (12) directed onto the sample (1) and reflected by the latter in a first photorefractive/electro-optical element (4). In addition, a second reference beam (11) identical to the first reference beam (10) is superimposed with a second measurement beam (13) identical to the first measurement beam (12) in a second photorefractive/electro-optical element (5). Mutually inverse voltages are applied to the two photorefractive/electro-optical elements (4, 5). The light emerging from the photorefractive/electro-optical elements (4, 5) is converted into electric signals which are subtracted from one another prior to the signal evaluation. Also specified is an arrangement for implementing said method.

主权项

1: A method for laser-optical detection of a surface movement of a sample (1), whereby a first reference beam (10) obtained from a laser beam (3) is superimposed with a first measurement beam (12) obtained from said laser beam (3) directed onto the sample (1) and reflected by the latter in a first photorefractive/electro-optical element (4), and the light emerging from the first photorefractive/electro-optical element (4) is converted into a first electric signal and then evaluated,whereina second reference beam (11) substantially identical to the first reference beam (10) is superimposed with a second measurement beam (13) substantially identical to the first measurement beam (12) in a second photorefractive/electro-optical element (5) and the light emerging from the second photorefractive/electro-optical element (5) is converted into a second electric signal that is subtracted from the first electric signal prior to the evaluation, and mutually inverse voltages are applied to the two photorefractive/electro-optical elements (4, 5).