Technologies for the formation of a piezoelectric transducer on the surface of an acousto-optic modulator crystal

Research into the application of multi-element transducers in acousto-optic modulators and deflectors has been conducted in several domestic and foreign studies. It has been found that multi-element transducers offer advantages over single-element ones, primarily due to their ability to generate a scanning acoustic beam with frequency variation. This leads to an expanded operational frequency range of the device. Furthermore, the focusing of acoustic energy into several main maxima (lobes) of the radiation pattern helps achieve relatively high diffraction efficiency (~2-4%/W) across the entire operational frequency band due to isotropic light diffraction on the acoustic beam. However, despite these advantages, multi-element transducers have one significant drawback. Depending on the magnitude of the phase shift between the elements of the driving structure, the radiation pattern of the generated acoustic field may have two or three main maxima (lobes). Since the operation of the acousto-optic device occurs at a selected lobe, this results in undesirable losses of acoustic energy and reduces the diffraction efficiency of the deflector. The paper presents the results of fundamental research into existing technologies for the formation of piezoelectric transducers on the surface of high-frequency crystals for acousto-optic modulators. Based on existing solutions, a technology for the formation of a piezoelectric transducer on the surface of the sapphire crystal structure for an acousto-optic modulator has been proposed.