Application of Spectral Analysis for Diagnostics of Precision Motion of Optical and Mechanical Units

We perform spectral studies of the vibrational phenomena which are caused by imperfection of the optical and mechanical units used in the technological process of applying an antireflection coating to the surfaces of large-scale optical elements. The ways of minimizing the negative effect of the revealed vibrational factors are indicated. In particular, it is shown that a decrease in the amplitudes of the low-frequency spectral components of the motion velocity of the treated elements due to the proposed modification of the optical and mechanical units allows one to create more uniform antireflection coatings. The spectrum of the laser-beam displacements spectrum in the near and far fields is also studied experimentally for various mechanical impacts on the optical and mechanical parts of a fiber laser system. It is established that the vibrations are nonlinear and, at certain impact frequencies, the laser beam in the far field oscillates at frequencies that are multiples of the impact frequency.