Measurement of small vibrations of objects using intracavity detection of radiation of a two-mode gas laser

A study was made of the feasibility of using two-mode gas lasers in remote detection of small vibrations of objects. Vibrations of ~ 10^–3λ amplitude (where λ is the radiation wavelength) were detected at a distance of 3–5 m in a frequency range up to several megahertz. An estimate was obtained of the maximum sensitivity of one of the proposed techniques for the detection of vibrations.