Development of an experimental device for measuring the internal stresses of single crystal diamond plates

The paper presents a stand for measuring the internal stresses of monocrystalline diamond plates. The device is necessary to assess the quality of single crystal diamond plates as promising materials for quantum sensing. The use  of diamond plates in engineering and instrumentation is limited by their quality. The device under development is used to assess the quality of the diamond plate according to the internal voltage indicator. The resulting device is an  optical microscope with a modified polarizer system based on the phenomenon of double refraction and capable of detecting changes in the anisotropy coefficient of the sample under study. Also, software was developed for the  stand that allows analyzing the received data. The result of the work of the stand is a map of the internal stress distributions in the test sample. The stand was tested on monocrystalline diamond plates with various anisotropy  indicators. The results showed the effectiveness of the developed device, which recorded the internal stresses in the plates in all areas of graphitization, in places of cracks, etc.