Interferometrisches Messverfahren fuer Absolutmessungen sowie dafuer geeignete Laserinterferometeranordnung
Known similar measuring process and measuring setups have the disadvantage that their measurement resolution by no way approaches the resolution achievable using other methods and that these processes are unsuitable for measured distances which vary within an extreme range. This disadvantage is solved by the measuring process according to the invention by the fact that two measuring interferometers are used, each with its own measured distance, to which the beam of the same laser is applied, whereby the reference distance formed from the arithmetic sum or difference of the two measured distances is kept constant. Thereby at least one interference signal which is measured by photodetectors is generated from the two interfering partial beams. In the actual measuring process, the air wavelength of the laser beam is continuously tuned within a wavelength range free from modal jumps between two wavelength values and the integral phase changes of each of the interference signals is detected during wavelength modulation. The measuring distance can be calculated from the phase changes and the length of the reference distance. The measuring process and the laser interferometer setup are suitable in particular for absolute distance measurements.
DE 1993-4314488 A: 19930503