Development and manufacturing of an electro-optical modulator based on the Pockels effect

Presented are the results of development and production of an electro-optical modulator based on the Pockels effect, which is observed in nonlinear optical media with double refraction and consists in a linear change in the refractive index of an extraordinary ray depending on the external electric field strength. Using the Pockels effect and the interference of ordinary and extraordinary rays, it becomes possible to control the transparency of a nonlinear optical medium. Lithium niobate LiNbO3 is chosen as the optical nonlinear material. The stages of development of the technological process, production of the optical modulator, including mathematical modeling, manufacturing products from nonlinear lithium niobate crystals are considered. The mathematical model of the Pockels effect is systematized using uniaxial crystals as an example. The modeling results are used to design electro-optical modulators. The technological process of sawing, grinding and polishing a lithium niobate crystal is described, a method for grinding the crystal with powder of different fractions of aluminum oxide is proposed. The body of the electro-optical modulator is manufactured by photopolymer printing. Modulation control is performed by means of an external electric field from the manufactured power supply unit. The results of experiments on recording conoscopic images are presented, the visual analysis of which shows the high quality of the lithium niobate crystal and the absence of internal defects. The studies of the electrooptical modulator demonstrate a sufficiently high correspondence between the experimental results and the described theoretical model.