Measuring method of piezoelectric displacement by making use of laser interferometer and laser interferometer for making the same

摘要

When using the method of measuring piezoelectric displacement of a sample by making use of laser interferometer a portion of the interferometer, in which the rays pass through different tracks and where the sample to be measured is placed, is fixed within a container with regulation of environment temperature. Then, different temperature values are successively set and using the laser interferometer, the magnitudes of displacement of the measured sample are read out. The displacement magnitudes are then converted to a piezoelectric constant of the measured material. Disclosed is also a laser interferometer for making the measurement, said interferometer comprising a laser, at the outlet of which, there are arranged on a common optical axis a half-wave plate (2), a polarized divider (3) and a first quarter-wave plate (4). Behind said first quarter-wave plate (4), there are arranged on a common optical axis (4) a first mirror (5) and particularly to said optical axis, in the place of the polarized divider (3), co-axially therewith and on one side thereof a second quarter-wave plate (7) behind which a second mirror (8) is situated. From the other side of said polarized divider (3), there is arranged an optical compensator (9), behind it a polarizer (10) followed by a detector (11). The sample (6) to be measured (6) lies on a connection line between the first and second mirrors (5,8).