Acoustic emission damage accumulation monitoring during mechanical and thermal strain of paratellurite monocrystal

The paper considers the problem of detecting defects in paratellurite single crystals using the acoustic emission method. For the first time, research was conducted on single crystals of natural geometry installed in an acousto-optic cell used in devices such as acousto-optic modulators, deflectors, and spectral filters. It was found that high-frequency acoustic signals in the operating frequency range of 27–60 MHz do not affect the registration of acoustic emission signals. Complex criteria were proposed and experimentally confirmed that allow one to detect moments of formation of crack-like defects in paratellurite single crystals under the action of mechanical stresses and temperature gradients based on the parameters of acoustic emission signals. The proposed approach allows one to determine the actual state of a paratellurite single crystal under the action of both mechanical and temperature stresses.